Science

You can apply for this course online/ offline with the required information. To be eligible to apply for this course, you need to have passed B.Sc. with Statistics and Mathematics as optional subjects and must have secured minimum 50% in Statistics at graduation level (for SC/ ST-45%).

Sorry, it does not offer M.Sc in analytical chemistry.

Yes, you can get private jobs after completing M.Sc in electronics and communication engineering. Some of the industries you can get employed in are mentioned below (Both private and public):
Research & development laboratories
Design & manufacture of Analog & Digital appliances
Industries related to VLSI, Embedded systems and DSP
Defense organizations like DRDO
Electrical products manufacturing sectors & companies, such as Intel, Philips, Mistral, Ample Communications, Ibex, Spa Computers, Cueflux Technologies Pvt. Ltd. , EmLabs, eSpark Infotech Pvt. Ltd, I Micro System, Adamya Computing Technologies, Sonata, etc.
Regards.

You should have pass with 60% and have to give entrance test for PU.

No, you don't have to study biology in B.Tech entrance exam. You have to study PCM.

No, maths as a subject in +2 is important for B.Com(Hons.). It's not important for you to add it in the best four though.

There are over 13 Distance/Correspondence M.Sc. In Science colleges in Mumbai. Please refer to the link provided below for a detailed list of colleges which offers M.Sc. Courses via distance/correspondence. You should be able to navigate to a college of your choice using the filters on the web page. https://www.shiksha.com/science/colleges/distance-correspondence-m-sc-colleges-mumbai-all.

Could you please be a little more clear about the question. Do you mean the general electives in college or the 5th subject in +2?

It's totally based on your 10+2 syllabus.

Eligibility Criterion for lateral entry in MCA:
Eligibility criterion for admission through lateral entry differs according to University. Admission to the programme is based on the scores obtained in qualifying exam as well as in interview. Regards.