India

The eligibility criteria is BE/B.Tech or post graduation degree from a recognized university or any integrated degree from BITS. BITS integrated degrees are of four years duration. As your graduation degree (B.Com) is of 3 years duration, you are not eligible to seek admission in BITS Pilani.

Both the institutes are good, but I would prefer NDIM, New Delhi as they have received top placement package of 24 LPA and average package of 6.5 LPA. Therefore, prefer NDIM.

You can refer to following link for the list of top MBA B-schools in Rajasthan:
https://www.shiksha.com/mba/ranking/top-mba-colleges-rajasthan/2-0-121-0-0

Hello total fees for four year engineering course is around Rs 6,00,000/-. It varies from college to college depending on facilities provided.

Yes, but if you want a career growth, you must have an additional qualification too.

BITS - Pilani is a decent college for MBA in Rajasthan.

SRM and SASTRA are known colleges in South.
You can check the below mentioned link:
https://engineering.shiksha.com/be-btech-in-mechatronics-engineering-courses-in-tamil-nadu-ctpg