M.Com

You can get all the information from the following link:-
https://www.shiksha.com/accounting-commerce/colleges/m-com-colleges-valsad.

Yes you're eligible
But you can't do it from Top B schools as they will look for your last academics. But you can do it from decent colleges with a decent package.

You can go for both. While doing M.Com on regular basis. You can do a Diploma on distance basis. You will get do degree/certificate at same time. Government validates getting 2 degrees at same time one as regular one as distance.

Get fees, placement reviews, exams required, cutoff & eligibility for all courses. Master of Commerce (M.Com.) (Part Time) (2 years).
refer link: https://www.shiksha.com/university/jnu-jawaharlal-nehru-university-delhi-4225/courses/mcom-bc

Find Fee Structure, Course Duration, Reviews, Cutoff for M.com at Institute of Distance and Open Learning - University of Mumbai for 2022 from the link given below-
https://www.shiksha.com/college/institute-of-distance-and-open-learning-university-of-mumbai-santacruz-east-10303/courses/mcom-bc

For M.Com. in Accounting and Financial Management at MSU - The Maharaja Sayajirao University of Baroda, Vadodara such as cutoff and placement,
Refer link: https://www.shiksha.com/university/msu-the-maharaja-sayajirao-university-of-baroda-vadodara-37071/course-m-com-in-accounting-and-financial-managem

Integrated B.Com. + M.Com. at Tezpur University - TEZU such as cutoff, placements, fees, admission, ranking & eligibility.
refer link: https://www.shiksha.com/university/tezpur-university-tezu-269/course-integrated-b-com-m-com-267791

You can pursue a B.Ed course after B.Com. Bachelor of Education at LPU is a postgraduate course undertaken by those candidates who aspire for the teaching line. The B.Ed programme aims to prepare teachers as per NCTE guidelines through a comprehensive curriculum of LPU. This university offers intens

You need to pass BHU PET exam to get admission in Mcom.

Yes, You can choose M.Com after BBA as many colleges take admission. But if you do it after B.Com u will have great knowledge and practice of topics which will help you in your entrance of M.Com.