CAT

You can apply for IIT-D/B/KGP, K J Somaiya, Management in Delhi University, BIM-TRICHY and LBS-Delhi are some good colleges you can apply to. As you have work experience you have chances of converting a premier school.

You can try for:
ITM Mumbai
Balaji Institutes Pune
XIME Bangalore
Christ University Bangalore
Flame University Pune
MIT Pune
IPE Hyderabad
Kirloskar Institute of management
ICFAI Hyderabad
ASB Coimbatore.

CA and CAT both are nowhere related. But, it would be helpful if you finish it first because the CA tag will give you additional benefits during selection and placements.

With this percentile you won't get any good college. Reappear next year for the exam and score well.

You will get a call from every good college except IIM-A and B with this score. Your B.Tech score might be the reason for this.

I am not too sure. CAT cut-offs are around 85 percentile, I guess.

CAT is held in the month of November or December every year. There are 3 sections in the paper comprising of Quantitative Aptitude Verbal Ability and Data Interpretation and Logical Reasoning. CAT is accepted by IIMs and other top B-schools for admission to their PGDM/MBA programmes.

If you have a below zero percentile in Quants you will have to explain it in the interview also, some colleges may not give you a call because of the negative marks.

85+ percentile will help.