Hi, in order to become a member of the faculty at an IIT institue or any other faculty role in TIER-1 colleges(7 IITs, 5NITs, DTU, BITS and IIITH) you will need PhD degree in teaching from a reputed college.

Apart from this you are required to have a good amount of work experience which change according to post in the faculty system you wish to apply for:

Professor: To become a professor, you need to have a total of 10 years of experience, of which you need to have a minimum of 4 years of experience as an Associate Professor or a designation in an equivalent position. The experience can be in the fields of teaching or research or it can also be industrial.

Associate Professor: To be eligible for the post of an Associate Professor, you must have a total experience of 6 years, of which three years of experience should be in the post of an Assistant Professor or in an equivalent position.

Assistant Professor: An Assistant Professor needs to have a PhD and 3 years of experience in the field of teaching or research or industry.

Research Experience : Experience of international post doc from Tier – I institutes, and in some cases people with PhD from top international Universities which are admitted without a Post-doc. Tier-II institutes will not insist on postdoc and depend upon a number of reasons.

Publications : With the wide range of responsibilities for both Tier-I, Tier-II and Tier-III institutes.

In the interview round your communication skills and teaching skills will be tested by the Head of the Department. Once, you get any TIER 1 college, you need minimum 10 years of experience to be promoted.

Ph.D. is the necessary and basic minimum qualification to become a professor in IIT/NIT. It is advised that you either contact the university or check out the eligibility criteria before applying  applying for the faculty recruitement.

You can see the NIT recruitement rules and application form from the link below

https://www.nitrkl.ac.in/facultystaff/Career/Teaching.aspx

You can view current openings in IIT branches from the link given below:

https://www.iitsystem.ac.in/?q=facultyrecruitment/publicview

Good Luck