IIM Ahmedabad - Indian Institute of Management Eligibility

Please refer selection criteria for all three colleges in their respective websites. Usually, it changes every year and has components of your past acads, work experience, CAT score and What/PI score.

Yes you're surely eligible. You can get details on cutoff and admission process below.
https://www.shiksha.com/mba/course/post-graduate-program-management-indian-institute-management-iim-a/1653

Yes you're eligible,
Candidate must have completed graduation with at least 50% marks or equivalent CGPA (45% for SC/ST/PWD/DA) from a recognized UniversityFinal year student can also applyMust have obtained valid percentile/score in CAT-2016/GMAT (at least 700) not before December 15, 2014(Overseas Indian candidates)
Note - It is mandatory for a final year student, who is provisionally admitted, to submit the mark sheet and degree certificate of the final year bachelors degree examination held on' or before June 30, 2017.

you need to score around 99 to 100 percentile on CAT.

Eligibility-
Candidate must have a Bachelor's Degree, with at least 50% (45% in case of SC/ST/DA category) marks or equivalent CGPA
Must have appeared in CAT/GMAT and obtain qualifying score
Admission Procedure-
Admissions are done on the basis of score in CAT/GMAT and Academic Writing Test followed by personal interview
Only top 50 candidates or top 1% of the applicants will be shortlisted for AWT and PI on the basis of there CAT percentile
https://www.shiksha.com/mba/course/post-graduate-program-management-indian-institute-management-iim-a/1653

IIM admits students to PGDM based on CAT exam results. All graduate wih greater than 50% marks are eligible to appear for CAT. You will have to be score very high to get admission in IIM Ahmedabad.

I don't think you will get an interview call from IIMA. IIMs put a individual score cutoff of 60% for all past academic performance. If you are below that, then you will not be considered for the interview. However IIMs call top 100 students in all streams for the interview, irrespective of their academic performance. Hence if you can secure top 100 rank in CAT, you will get a call from IIMA.

Dear student,
Eligibility : min 50% in graduation with good percentile in CAT and rest depend on ur IQ level, communication skills and knowledge
So do well in Cat and admission process
All the best

Yes, you are eligible for IIM Ahmedabad. All you have to do is to secure good percentile in CAT.
All the best.