Hello,
Answering your query pointwise as asked,
1. The RERA registration is based upon the area and number of apartments to be built. You need to check with the builder if the RERA registration is required or not. In any case, it won't affect your eligibility for exemption u/s. 54F.
2. No certificates or documents are to be submitted with the income tax return to justify your claim of exemption u/s. 54F. though you need to keep all relevant proofs relate to investment and completion certificate if required in the future in case of any query by the department. The exemption is claimed in the return by the assessee on a self assessment basis.
3. Yes.
4. Yes.
5. The main intention of the law is to get investment in residential property and on completion of the construction of the property. There case laws favoring the assessee in case the completion is not completed with the prescribed period of 3 years. Exemption stands in such cases as well.
I hope that this answer satisfies your requirements.
Regards,
CA Hunny Badlani