Hi Tanmoy,
You can purchase 'blocks' of CATs from
MGMAT, Veritas or Kaplan.
However, there's a bigger 'issue' here that you have to consider. If you have not taken many CATs during your studies, then you might not be properly prepared to take your GMAT in 10 days. "Cramming" in lots of CATs during this time is NOT a good idea - you'll be far more likely to 'burn out' than actually improve. As such, you might have to reschedule your Test Date.
1) How long have you been studying?
2) How have you scored on your CATs so far (including the Quant and Verbal Scaled Scores)?
3) Did you take the FULL CAT each time (including the Essay and IR sections)?
4) What is your goal score?
5) When are you planning to apply to Business School?
GMAT assassins aren't born, they're made,
Rich