Yes, it’s necessary to register an Agreement for sale to make the transfer of Ownership of a Property legally valid,

Evidence in the Court: 

An Agreement for sale that’s registered can be used as valid evidence in court if there are any conflicts.

Transfer of Rights:

Registration of the Agreement Transfers the property’s rights from the seller to the buyer.

Complete the Transaction:

The sale or transfer of the property is considered complete and valid only after the agreement is registered.

The Registration Act, of 1908, the Transfer of Property Act, of 1882, and the Real Estate (Regulation and Development) Act, of 2016 mandate the registration of an agreement for the sale of immovable property. By registering the agreement for the sale of an immovable property, it becomes a permanent public record. Further, a person is considered the legal owner of an immovable property only after he gets such property registered in his name.

RERA Carpet Area
Prior to RERA, there was no industry wide standard definition for calculation of apartment area. Now,
RERA provides a standard formula to calculate carpet area.
It is now mandated the developers sell their apartments based upon the MahaRERA carpet area.
According to the Act, Carpet Area means net usable floor area of an apartment, excluding the area
covered by the external walls, area under services shaft, exclusive balcony or verandah area and
exclusive open terrace area, but including the area covered by internal partition walls of the apartment.
This standardisation of the carpet area definition ensures that homebuyers buyers are not misled. Pre-
RERA the loading factor was high; therefore, the saleable area was inflated. The effect of this is that the
rate per square feet on the saleable area is reduced. Using the above- mentioned standard for carpet
area will ensure that there is clarity on the usable area. This also helps in the analysis of cost per square
feet. Comparison between the different projects also becomes easier.
Therefore, the allottees must ascertain the carpet area of the apartment under consideration.

Buying an under construction property in Mumbai can be a good option if you consider the following factors:-

Pros:-

• Price:-  Under-construction properties are usually cheaper than ready-to-move-in properties, with price differences of 10–30%. 
• Return on investment:-  You can sell the property for more once construction is complete, and the surrounding infrastructure may also improve during this time.
• Customization:-  You can personalize the property to your preferences.
• Payment flexibility:-  You can make payments in installments, rather than paying the entire amount upfront.
• RERA compliance: RERA regulations ensure transparency and protect buyers’ interests.
• GST:-  Under-construction properties are subject to GST, with a rate of 12%.
• ______
• Cons.
• However, there are also some potential drawbacks to consider:
• Delivery schedule: Construction delays can occur, which may mean you have to make more mortgage or rent payments.
• Project completion: There’s a chance that the project may not be completed at all.
• Tax benefits: Only ready-to-move-in properties are eligible for tax benefits.

+ Before investing in an under-construction property, you should check the developer’s reputation, RERA registration, legal approvals, and construction timelines. Ownerg.com has Expertise in this area.