Dear @Gyan_Dev
If you have proper documents, you may file a complaint against your builder to the Uttar Pradesh Real Estate Regulatory Authority (RERA). For more details, read this: Where to file complaints about real estate, building, and property?
Additionally, you may also lodge a public grievance to the Noida Development Authority through the Jansunwai-UP (Samadhan) portal of the government of Uttar Pradesh. In this case, attach all the supporting documents.
If initially not resolved, use the same reference number or acknowledgement ID and re-submit the grievance through the Jansunwai portal.
The resolution process may take 30 to 60 days. If still not resolved, you may consult with a property lawyer or your nearby property expert.
Still, need help? Ask by replying to this post.