CAT

Likely November 2019
Other Important Dates
Registration
Likely Aug 2019
Admit card available
Likely Oct 2019.

For admission in MBA, you can have Bachelor's degree.

You can prepare for this year's CAT. You can allot 1/2 hour every day for preparing CAT. As CAT syllabus is more of logical, analytical and reasoning, so it's easy to give time for CAT preparation.

80 percentile is not enough to get a seat in IISC. Generally CAT cut off for MBA-IISC is around 95-96 percentile.

You can give CAT when you are in final year and after completing graduation. CAT score is valid for 1 year so you can give a try in final year. As you are graduating in 2020, you can appear for this year's CAT.

Your percentage is not seen in the interview, because interview round is an individual assessment. But, your overall score gets affected. If the interviewer knows your score it may psychologically effect his questions and judgement.

For taking admission in IIMS, there is only required of CAT exam no need of any other exam.

In graduation, you need at least 50% marks for CAT or GMAT from any recognized University.

Yes, there are many exams:
CAT Entrance Exam.
CAT Full Form: Common Admission Test.XAT Entrance Exam.
XAT Full Form: Xavier Aptitude Test.
GMAT Entrance Exam.
GMAT Full Form: Graduate Management Aptitude Test.
CMAT Entrance Exam.
MAT Entrance Exam.
ATMA Entrance Test.
NMAT Entrance Exam.
SNAP Entrance Exam.

No, there is no restriction on number of attempts for giving CAT entrance exam. You can sit for CAT entrance exam multiple times.