From FY 2023-24 on words those who opted Old Regime after due date [ 31st July ] automatically converted into New Regime.
Those who opted New Regime after due date late fee of Rs.5,000, which shall be reduced to Rs.1,000 if your total income is below Rs.5 lakh.

Section 80CCD(2) of Income Tax Act

It is for employer contribution. It applies to only salaried individuals.

A maximum deduction of 14% of their salary (basic + DA) contributed by the Central Government or State Government towards NPS.

A maximum deduction of 10% of their salary (basic + DA) contributed by any other employer towards NPS.

It is applicable only an Old Regime.