Dear Sir,
Hope you are doing well !!
1. Yes, your understanding is correct.
There is no GST on sale of complex/ building and ready-to-move-in flats where sale takes place after issue of completion certificate by the competent authority.
2 & 3. It is advisable to get the valuation of the property done from the registered valuer.
Government-approved valuers follow a standard process for the valuation and provide a detailed report.
4.it would be treated as LTCG.
For properties that are acquired/inherited prior to April 1, 2001, you have the option to take the fair market value of the property as of April 1, 2001, in place of the cost of acquisition. So, the concept of fair market value is important for finding out the cost of acquisition, for capital gains purposes.
You can obtain a valuation report, from a valuer who is registered under the wealth tax rules and who is recognised for determining the fair market value for income tax purposes.
We may assist you for the same.