B.Tech

If you have an interest in airforce then you should go for airmen otherwise do engineering in CSE from Galgotias.

Enhance your technical skills by joining short term courses of a domain of your interest, this will improve your practical skills and make you ready for the technical round of any company.

Check the link below for details:
https://www.shiksha.com/b-tech/course/b-tech-in-computer-science-and-engineering-raj-kumar-goel-engineering-college-rkgec-hapur-183607

To get a good government college, your rank must be under 50000 (General rank). You can try for BITS/ COMEDK and VIT. These are the best pvt. colleges for CSE. If you have any questions, you can directly. Thanks.
Best of luck.

Check out the link below for colleges:
https://www.shiksha.com/b-tech/colleges/b-tech-in-biotechnology-engineering-colleges-lucknow

These are some of the good online coaching institutes that you can opt for.
https://www.misostudy.com/
https://www.plancess.com/

It's a decent college but to know the exact scenario for faculty and placements get in touch with the current students through social media or in person.
Check the link below for more details:
https://www.shiksha.com/college/techno-india-salt-lake-salt-lake-city-kolkata-48911/reviews

As you left B.Tech after second year then why do you want to restart acedmic in which the you could not do well. It will be better if you opt for BBM-MBA and restart education with clean slate.

You need to opt for JEE Mains examination.