Hii..

As you Mention here that you are in your BSc degree so BSc degree are of  3 year  and according to Jee main eligibility criteria you have only 3 attempt after your 12 ..

And as mentioned that you want to take admission in IIT...so   3 year after your 12  you will not able to apply for JEE main and to get admission in IIT college.. but if you are in first or second year of your BSc degree then you are able to apply for JEE main

For the eligibility criteria for a man go through this link:

https://engineering.careers360.com/exams/jee-main

All the best!!