Science

Please check for your eligibility to appear for the IISER entrance test from the criteria mentioned at the link provided below:
https://www.shiksha.com/science/exams/iiser-entrance-exam.

No, the Central Universities those are involved in a combined entrance exam follows a common counselling process too. So, its sad to hear but you can't get into this year. You may try next year with proper planning so that you can't miss the exam.

TS EAMCET 2018 College Predictor
Use your TS EAMCET 2018 rank to see where you can get admission at the link provided below:
See the courses, colleges & rounds you may crack
The result is based on admissions data of TS EAMCET 2017
Get resources & insights on colleges & courses
https://www.shiksha.com/b-tech/resources/ts-eamcet-college-predictor.

Please check for your eligibility to appear for the NIMCET from the criteria mentioned at the link provided below:
NIMCET 2018 eligibility criteria: https://www.shiksha.com/university/national-institute-of-technology-durgapur/exams/nimcet
Regards.

MIT is the best institute in the world. For getting admission in MIT you have to take SAT and TOEFL exam but this is not sufficient because the admission process is holistic means they will also see your other qualities like extra curricular activities, personal essay, family background and many more. If they're thinking about you then they don't see about your income potential. They want only talent. But the admission is very competitive like out of 100 only 7 to 8 can get admission in MIT.

Yes of course. But first have to go through the websites of the desired colleges whether they are giving this or not. In almost every institute you can do M.Sc. Biotech after B.Sc. Microbiology.

Yes, definitely, you will got an engineering in any state, as per your JEE marks.