Independent to fruits of action and those performing bounden duties are true Sanyasi or Yogi, not those who do not create fire (of Yagya /projects) nor are active (to deeds).

Know him duly Sanyasi, the unflustered, phlegmatic individual who neither envies nor aspires; free from all dilemmas, (he for sure knows the doable), lives with serene happiness, liberated from all bonds as said O’ mighty armed!.
Sanyas is about actions detached, not inaction or recluse in physical sense. Truly, Sanyas is a mental disposition where one remains duty bound without any interest and intention to enjoy fruits of actions. Sanyasi is engaged in deeds of humankind and remains dedicated to respective ethical hierarchies, (i.e. family, society, state, country, humankind and nature kind). He has to create fire of yagya i.e. actions and deeds of utilitarian value i.e. Purusharth and stay active. Recluse and those who leave their family without fulfilling obligatory duties are not Sanyasi. In ancient times it might be the necessity to dedicate oneself physically to reach out to the masses, but in today’s time. One can reach out to masses, and make opinions from distance. Or even remain detached and dedicated to his own social peripheries, which is much larger than it used to be earlier. Creating fire refers to yagya, but yagya refers to set of actions, not just worshiping around the altar of fire. This is immediately complemented in shloke by Ni- agnih-no cha- akria (neither those not creating fire nor those non-active). The scriptural terminologies like Sanyasi, Yagya and Yog etc. needs to be logically understood. Without enjoying fruits of actions, anyone can dedicate his works, to the society or nation. Saffron dress and celibate life are also not the signs of Sanyasi, as most tend to believe. One may be partly dedicated to family responsibilities, and still dedicated to society, simultaneously. Although certain organization may impose such restrictions on their recruits, but, it would not ensure total selflessness, as they may still be attached to their parents and siblings. How can one ensure that only by not marrying one will be fully dedicated to society? While people, in their married life, can have hobbies and they can dedicate their time to those hobbies, why not to social concerns as hobbies, fully detached. State of mind qualifies the criteria of Sanyas modes.

Self-abnegation of desire-led-actions ‘before-hand’ is Sanyas (Renunciation) as Sung by erudite and knowledgeable. Disownment of the fruits of all actions ‘post-act’ is said to be Tyaga (Abandonment) by the experienced visionaries (after results materialized).
Arjun raises a doubt and gets confused between Tyagi (abandonment) and Sanyasi (renunciation). In shloke 18.2, Sri Bhagwan explains that Sanyas is about bequeathing expectations from actions beforehand and Tyag is abandoning the gains and fruits earned post-actions. Sanyasi is with a selfless objective. Sanyasi is not inactive, carefree and thoughtless.

Sanyas is a state of mind causing one to act without desires and selfishness. It does not mean rejecting all responsibilities towards family, professional or society. People can become categorically or contextually Sanyasi in their day-to-day life as well. Crossing roads in uncivilized cities is not easy for elderlies. A person crossing roads helps an elderly women with no intention to gain anything from her, demonstrates a sanyasi’s character in the act. Social workers are Sanyasi as they dedicate to the society selflessly, even when they are married and raise family. Some even sacrifice their cosy jobs to help build the nation. Sanyasi is said to be Brahmachari, which in turn is interpreted as being celibate. However, Brahmcharya semantically means ‘the one living with the laws of nature’. Marrying and not celibacy is nature along with other eternal and spiritual laws to abide by. Celibacy is not the ideal recommendation for the human race. To sustain humanity, given the death as law of nature, births are essential. Extinction is not our goal, sustainability is. However, for those who dedicate themselves to humanity at a young age, owing to their natural inclinations, can remain celibate. However, Sanyas is recommended in the last quarter of the life after all responsibilities are over in previous three phases of life. Scriptures prescribe four quarter of life based on ethical hierarchies: 1. Duties towards self (Brahmacharyasram). Learn and be skilled to contribute; 2. Duties towards family (Grihasthasram). Raise and educate families 3. Duties of mentoring youngsters in society (Vaanprasthasram) and finally 4. Duties to the humankind (Sanyasasram). Thus, every individual is able to contribute to each ethical hierarchy in due course of time. The life was well organized by Rishi having scientific bent of minds. The conventionalist cannot create such rules in society, instead they digress as they remain attached to the words and not essence.
Time changes, and so the applications may be revised. This is what thinking minds would do. A pragmatic mix of these phases may be implemented at any part of time. For example, even in student life, one may be dedicated to nation selflessly. Army men dedicate their life for nation yet they care for their families too.
Mother Terresa, Mahatma Gandhi were the great Sanyasi’s. Despite the great success they brought to the country and humanity, they  never tried to benefit personally. Mahatma Gandhi never tried to be the President or PM of the country. Most founding members of RSS and Acharya who dedicated their life to build Vidyalaya’s (schools) and nurture qualities in pupils were selflessly dedicated. Technically, they were Sanyasis, representing the element of God in them.