Hello kuldeep,

Yes, if you have done diploma from any recognized university or authorized , you are eligible for  IIT JEE  EXAMS. I would also like to tell you after completion of 12th you can apply for IIT JEE EXAMS.

BEST OF LUCK.

Dear kuldeep, 

To apply for jee or iit you need to qualify your 12th with atleast 75% in PCM. So if you are eligible then go for it but if you are not then you can't. By the way polytechnic is also a very good subject so do your 100% in this . This Course have a very large and wonderful scope in future.

All the best for future