I did not get you. Let me answer on an assumption like this.
This year, 2020, you have allowed 60 days paid leave due to lockdown
Now in 2021 January, when you decide the eligibility for annual leave/ PL/EL, can this 60 days allowed as paid leave in 2020, b considered as days worked?
YES, because, any paid leave will be counted as days worked for all purposes including leave eligibility and even for gratuity. Now for leave eligibility one has to complete at least 240 days. For this purpose, obviously, the lockdown period should be taken as days worked. Since the number of leave earned in 2021 will be based on the actual days physically present, these 60 days will not be counted for how many leaves an employee earns. I repeat, FOR ELIGIBILITY (to decide whether an employee is eligible to leaves, ie, for 240 days purpose,) all paid leaves will be counted as days worked but one will EARN leaves only for the actual days worked or physically present. Obviously, the number of leaves each employee earns in 2021 will be lesser than any normal year.
The matter of eligibility and earning of leaves based on physical working days are very clearly mentioned in the Act, there is no need for a document for this. Obviously, if you wish to give leaves for the lockdown period also, then you can document it.
Hope I have understood your query in the right way. If not, please let us know .