Shares: Indexation after 31st Jan 2018

Dear Sir,

I purchased few indian shares of a company in 2010 and sold them in 2021.

I understand that the grandfathering clause will be used to arrive at the cost of acquisition:

Max( Purchase price, Min(Sale price, Highest price of 31st Jan 2018))

But I'm curious to know if indexation is required to be done for the duration from 31st Jan 2018 to the sale date in 2021, to arrive at the final cost of acquisition, for the purpose of calculating LTCG/loss.

Please help