Hello Aspirant.

Candidates having a diploma can apply for JEE main examination but won't be allotted any NITs or CFTIs and 5 of the IIITs come under CFTIs

1 Gwalior

2. Allahabad

3. Jabalpur

4. Kanchipuram

5. Kurnool

Hence, you won't get admission into IIITs these through JEE main examination.

Try giving IIIT UGEE examination to get admission into IIITs.

Best of luck