What is my tax liability?

" What are tax implications?"

As it is, it will be short term capital gains, which will be added to your income and taxed as per slab rate.

"Can I save any tax? If yes, what are possible ways."

If by any means, the transfer of land takes place after TWO YEARS OF HOLDING PERIOD!!

I already had received an advance payment towards the same of Rs.1lakh. So, if I postpone the sale deed later to 1 year, Is it fine and Can I go ahead to save my taxes?

Which date will be considered as Date of Transfer if I postpone the sale agreement(i.e., Sale deed)?

Date of Actual receipt or Date of sale deed?

Agreement is not important.

Payment is not important.

Registration is not important.

Possession(Key) is important.

In this case date of possession will be treated as the date of transfer.

As per the Finance Act 2017 the holding period Should be more than 2years for  LTCG.