This is really good , that you have Qualify in NDA exam.But i am sorry to say that their is no different vacancy for IPS exam.

Now you have completed 12th standard but the minimum Qualification for IPS recruitment exam is Graduate.

IPS exam is conducted by UPSC. There are some criteria you have to follow for appearing in IPS exam.

Those candidate have completed graduation in any discipline from recognized university are eligible for IPS exam.

But your age should be in between 21-30years for general candidate.
In IPS exam their is provide age relaxation for OBC candidate is 3years and for SC/ST candidate is 5 years.

The maximum attempts for Sc/ST candidate is Unlimited. For OBC candidate it is 7 years and for general candidate it will be 5 years.
Also you must be citizen of India.

So from above criteria you have not matched to the Academic Qualification and Age Criteria