Diploma

Hello Shashank,
It's very nice to know about passion or likes of your bro. Yes, he can do diploma in animation after completion of his 10th. This subject is craze these days as there are plenty of job opportunities post this diploma.

Around 45-50 marks.

You can get direct admission to second year in Vishwakarma Institute of Technology, Pune. Here the fees is in the range from Rs. 1,10,000 - Rs. 1,20,000. Also, you can try COEP. As it is a government college, fees will be somewhat lesser. But, getting admission to COEP is quite difficult.

Hi,
You can pursue both a graduation and a Diploma course in event management. The eligibility criteria for a Diploma course is 10+2.
For college list:
https://www.shiksha.com/mass-communication-media/event-management/colleges/colleges-india

If you studied 12th then you can definitely appear for JEE Mains. If you joined Diploma after 10th, then you can't apply for JEE Mains.

If you complete your Diploma in ECE, then you can go for engineering that will help you to get a good job, or if you want to go abroad then you have to study more like MBA, then your chances of abroad becomes possible.