IIM Ahmedabad - Indian Institute of Management

See there is no percentage required for getting into iims,instead it is measured in percentiles. percentile means the percentage of candidate who have scored lower than you. For Eg:-If your percentile is 99.9% means 99.9% of candidate's marks is lower than yours. and generally,it is very competitive so you have to score above 99 percentile. good luck

yes IIMs provides distance learning courses

You need to join top coaching for MBA.
You can check the below mentioned link for more details:
https://edudrona.com/right-coaching-institute-mba-entrance-cat-xat-mat-cmat-snap-tiss/

You can write it in any year but colleges will take you only if you have completed graduation. So you should be giving it in your final year.

you have to give cat exam with above 98 percentile. you can take coaching from TIME in third year

To get admission in IIMA, your son will have to write CAT. Once qualified for interview, he will have to undergo WAT/PI process. If he clears that he will be able to join IIMA.

CAT percentile cutoff last year was close to 99.5 percentile. I guess based on your performance you will have to score a little more than the cutoff.

The faculty at IIMA is one of the best in India.

If you have missed the deadline this year then I don't think you can do anything. You can apply next year.

Yes you can, as long as you have clear the cutoff.