The time of the year you give GMAT doesnt really matter in terms of scoring. The percentile values for every score keeps changing, and every school considers your score along with the percentile value to be fair.
But it would help to take GMAT in the first half of the year if you can, so that you have ample time to retake it if needed, and also be able to apply to B-Schools as soon as the first round of application starts.
Regarding schools in India accepting GMAT,
ISB - need atleast 3 yrs exp
IIMA - PGPX - min 5 yrs exp
XLRI - min 5 yrs exp
This is not an exhaustive list. Just listing the top ones that come to my mind.
I am planning to prepare for GMAT .Could you please suggest which time will be best to give GMAT.what are the good colleges in india which accept GMAT score.