Executive MBA or FT MBA through CAT/GMAT

HI, Posting very first time on this portal as I am looking for a fair opinion. I am a science grad., MBA in mktg from a private instt. I am an average student with: X- 68% XII- 65.2% B.Sc. - 63.1 MBA- 2.63/4 Now, I am working for a we…

HI,
Posting very first time on this portal as I am looking for a fair opinion. I am a science grad., MBA in mktg from a private instt. I am an average student with:
X- 68%
XII- 65.2%
B.Sc. - 63.1
MBA- 2.63/4
Now, I am working for a well known pharma company as an Astt. Mktg. Mgr. and planning to opt for an Executive MBA from premier institute. My total work experience will be 2 years when i'll be applying next year.
I would like to know whether I should go for ISB the only option left with the current work ex through GMAT or should I go for FT 2 yrs course through CAT/ GMAT from any of the known B-Schools.
Above all, with such an academic background is there any chance to get selected for a known course, if I score good in entrance exam(CAT/GMAT) for the same.
Please reply....!!