Date of purchase for property sale to calculate CG

By date of allotment did you mean registration / agreement date or provisional possession date please?

Not registration,.  When developer gives a letter of allotment stating flat no.etc...or if in your case  provisional  possession may be if in such letter , developer states flat alloted to u

Thank you, that helps.

Developer gives allotment letter & it is different from possession letter and registration.

Somewhere allotment must be stated

No separate allotment letter was issued by the builder however after paying 20% of the property value the flat number was allotted and agreement was done, should I consider the agreement date as date of purchase? Also is it necessary to complete 100% payment of the property to be considered as purchase date?

After the flat allotment registration at registrar office and agreement with builder was done at the same time in Dec 2014

No builder will register a flat at registrar office on 20% payment. Please check again. But if it's correct then  Dec 2014 is purchase date.

This is a common practice in Pune, will go with Dec 2014 as purchase date then. Thank you for your help.