ELIGIBILITY
B.Des : 10+2 from any recognized board of education.
B.FTech: 10+2 from any recognized board of education with Physics, Chemistry and Mathematics as core subjects.
So yes you can give the entrance if you are currently in 12 or cleared 12th, as the maths is of class 10th. and in India maths is a compulsory subject till 10th. See some sample papers for more details.
There are a lot for coaching institute that will help you prepare for Nift.
write to me at rucha.t@gmail.com for more details.
hope this helps