1. If you had opted for construction linked plan,should you stop the payment due to the breach on the part of the builder of dealing the possession.
2. Since RERA is very new act, execution of the decree is not quite that as it is still in its nascent stage. I would not advise approaching RERA in your case.
3. NCDRC or NCLT is the best way to get your money back along with interest and compensation from the builder or possession along with interest in compensation.
4. That's up to your requirements. It's possible both ways.
5. The builder would have to follow the decree of the court. If he fails to do so, his properties would be attached in order to satisfy the claims.