Certificate

Hello,
Check this college predictor by Shiksha. By this predictor, you may get predicted information about the colleges you may get.
https://www.shiksha.com/b-tech/resources/ap-eamcet-college-predictor

You can pursue B.Sc course from IGNOU if you are not able to do it in regular. IGNOU is renowned in providing distance B.Sc courses.

Yes, you can get it.

After Passing 12th School gives different certificates like School Leaving Certificate (TC), 12th Marksheet, 12th Passing Certificate, Character Certificate and Migration Certificate. These are all provided by the school, School may take time to give you as it is issued after marksheet and generally it is given late. Migration is and important document as it shows that you have no dues with your previous Board/University and now you can change Your University/Board. So it is required while admission in college.

Placement doesn't depend on CGPA. It depends on the skill you got and knowledge you acquired. Yes, you have to maintain a minimum CGPA that is 8 or 7.5. No company hire employees on the basis of CGPA now.