Engineering in Bangalore

yes it is good for B.Tech.

I think nitte meenakshi institute of engineering is good, however I will suggest you to check the current rankings of different colleges and also check the seat matrix available.

I would prefer Bangalore, since a lot of opportunities and number of colleges in Bangalore is more. But you need minimum of 80/200 in NATA to be eligible for that, you can take that exam even now.

reva university comes under top universities in bangalore, as far as CS branch is concerned , you don't have to worry about placements, placement in CS branch is always good in most of the universities.

Bangalore is good place to study engineering.

MSME-Tool Room, Hyderabad (Central Institute of Tool Design) runs some job oriented short term courses. You can select one of the courses from them which you find better. Their website is:- http://www.citdindia.org You can also search IGNOU for certificate courses. If you want to be an entrepreneur then www.ediindia.org offers one year diploma programme "Diploma in entrepreneurship and business management" in distance mode. If you have the will power then you can go for AMIE also.You can also check Skill India programmes started recently to help persons like you.All the best.

DY patil college of engineering is best college with high ranking

Manish, after completing diploma in Mechanical you can get admission in 2nd year.of B.Tech that we refer to as lateral entry. As first year syllabus for all branches is same, so you can take admission in any branch of your choice.
You have to appear for Lateral Entry Engineering Test (LEET) for admission in 2nd year.of B.Tech. You must have min.of 60% marks in diploma to appear for LEET.
If you have not given LEET, then opt for good private universities like LPU, MIT, IIIT, DBU, etc. They offer world class environment to students along with good placements. Some even offer good scholarships to students. Check their websites.
Good luck.