Is Pension Received From Navy Taxable..?

Dear Friends,

Hope everyone are good,

I have a query regarding Navy Pension Taxability

One of my friend father received a arrears of pension from Defence of Accounts after a supreme court order and has received a lumpsum amount which is from 2017 till date and now onwards receiving pension regular, My question is that pension received from that department is it taxable..??

Thanks in advance

Regards

BALRAJ B G