I have given my NMAT on 23oct and want to give retake..So will i be able to choose the date for the retake accordingly ??

NMAT by GMAC is allowed a maximum of 3times, Hence once you give your exam, you're left with 2 more attempts.

Atkeast 15 days gap is must after every retake and the slot shall remain open til 18th December 2017.

You can also reschedule your appointment incase you miss out but with credit card only.

Since its your reatke you're advised to study sincerely and give your best shot.

Some preparation tips shared below.

1.You can navigate between sections and also choose the order of section, so choose your strength first, then the one you are least confident about and round it off with the last one at the end. It is important to make a good start as it affects your confidence, hence this strategy.
2.Never get stuck on a question and make sure that you skim the entire paper. Many a times, the easiest of questions are given at the end and it becomes difficult to see them, especially in the online format.
3.Verbal is not inferential, so be prepared for direct questions. The level remains easy to moderate.
4.This is not a neuron intensive paper and since the section selection, skimming questions etc. elements still prevail, time management is by far the most important of all the elements.
5.Keeping the eye on the clock is crucial and so is going after the easy questions first.

All d best.

Yes you can. After the gap of minimum 15 days you can re apply for the second attempt.

To re-schedule there are some charges.  You can check NMAT important dates and NMAT retake/reschedule charges here .

The NMAT exam are on going till December 18th, 2017.

Good Luck.