B.Tech

You can't decide anything with your marks, you should know about your interest. And your interest should be your engineering branch although if you are pass with 50%+ then you can take admission in any branch of B.Tech but you have to approach private colleges so please choose wisely as per your interest.

Hello dear,
Please give us your rank by which we can help you better,
Use TS EAMCET 2018 College Predictor:
https://www.shiksha.com/b-tech/resources/ts-eamcet-college-predictor

Hello dear,
Please mention your rank.
Use TS EAMCET 2018 College Predictor:
https://www.shiksha.com/b-tech/resources/ts-eamcet-college-predictor

Hello dear,
Use TS EAMCET 2018 College Predictor:
https://www.shiksha.com/b-tech/resources/ts-eamcet-college-predictor

You can try in private colleges for B.Tech.

Yes, of course, you will get admission.

No, you can't, Please reappear for compartment exams as you won't be eligible for B.Tech course without passing maths subject.

After diploma, you can go with degree level courses or PG diploma programs. B.Tech degree can be obtained with specialization in Automobile Engineering or Automobile design Engineering. Admission to the course can be done through lateral entry and thereby you can save one year. Post Graduate Diploma in Automobile Engineering is also suitable for you. Or else you can try for a job with railways, defense, government departments etc.

Yes, of course, you can do this. You are eligible for the same. Please apply for admission in any good college. You can use you work experience in your college life. You can join B.Tech.
Good luck