BCA

Hello Rahul,
The following are the top BCA colleges in Mumbai:
1)Don Bosco Institute Of Technology
2)St. Xavier's College
3)Atharva College of Engineering
4)Jai Hind College
5)Dr. BMN College of Home Science
6)Vidyalankar Institute of Technology
7)Mukesh Patel School Of Technology Management & Engineering
8)Vikas College of Arts Science and Commerce
9)IBSAR
You may also refer:
https://www.shiksha.com/it-software/colleges/bca-colleges-mumbai-all

Admission for M.Sc-PhD Environmental Science and Engineering is offered through JAM with following test papers: Biotechnology/ Chemistry/ Mathematics/ Physics . If you can clear JAM after BCA you can seek admission in Sc-PhD Environmental Science and Engineering.

As per the website, the college does not offer BCA.Please check: http://www.hindujacollege.in/Undergraduate_Degree

Hi Arjun,
For majority of the universities it's a 'no' if you don't have high academic grades and also you have a 3 year course. You may enroll into a MS program in India and complete the first year to be eligible.

'O' level course of DOEACC Scheme is equivalent to a Foundation Level Course in Computer Applications. Students can acquire this qualification by undergoing this course and passing the examination conducted by the DOEACC Society.

What exactly do you mean by government quota? As far as I know there is no government quota in any of the states.

Yes you can pursue B.Ed after BCA and D.El.Ed.

Yes you can opt for BCA from ECMT college, for details check link below:
https://www.shiksha.com/it-software/course/bachelor-of-computer-application-eminent-college-of-management-and-technology-ecmt-kolkata-barasat-253964