IIT

Minimum 65% in class 12th will be sufficient to be eligible in most of the courses of AI and ML.

First of all, you can't get IIT through JEE Mains percentile. You need to attend JEE Advanced exam. You are qualification for advance depends on your category. JEE score cards released yesterday only. There you can SEE your rank and cut-off for all categories. Cut-off for Common rank list is 87, for OBC is 66, for SC is 46, for ST is 34. You can check 2020 opening and closing ranks for various IIITs, GFTIs, and NITs.

To be honest you can't get admission in IIT from JEE B.Arch as first you need to qualify JEE Mains Paper 1 and then give JEE Advance after that you need to give AAT Architectural Aptitude Test ) conducted by IIT's after qualifying in all 3 exams then you can get admission in IIT B.Arch.

It depends for which subject one wants to give IIT JAM paper, every year jam conducting organizations release eligibility criteria.

No, if you want to get admission to IIT Gandhinagar on the basis of IIT Jam rank, then they won't take an interview. This thing is mentioned in IIT Jam brochure.