Hello Raja
Though under the general law, firm does not have a distinct legal identity apart from its partners, under the Income-tax Act, Section 45(3) transfer of a capital asset by the partner to a firm or by a Member of Association of Persons to the Association of Persons (AOP) by way of capital contribution or otherwise is chargeable to tax as capital gains of the previous year in which such transfer takes place. The amount recorded as the value of the capital asset in the books of account of the firm, AOP or Body of Individuals (BOI) will be deemed to be the full value of the consideration.
As the Partner is holding the land for more than 10 years, the gain would be LTCG
Now after the transfer in Case1: Income would be chargeable under PGBP and there would be no Capital Gain
Case 2 : There will be STCG in the year of transfer & COA would be the book value of asset