Hi Cheemala,

Are you referring to scholarships? If yes, Scholarships are awarded on various criteria.There is nothing called free seat in IIT's or NIT's but there are fee exemption or scolarships provided on various criterias and some of the scolarships given by IIT's are:

-Institute Merit-cum-Means Scholarship

-Institute free studentship

-Institute Notional Prize

-Institute SC/ST Scholarship

-Indian Women's Association at Bonn Scholarship...etc

Again, some of the scolarships offered are different in different IIT's or NIT's.

I am attaching a couple of links where you can get further details and if you want more details then i would like to suggest you visit the Institution's official website.

http://www.nits.ac.in/admissions/scholarships.php

https://students.iitm.ac.in/freshers-website/pages/scholarships.html

http://www.indiaeducation.net/iit/madras/fees-and-scholarships.aspx

Hope it helps.

All the best.