You need to pay the premium for the chosen policy term. On vesting, the sum assured + vested simple reversionary bonuses + terminal bonus, if any is considered as vesting proceeds. These proceeds can be used immediately to purchase an annuity to receive the monthly pension benefits. Or else, you can defer the annuity purchase to a later date. Depending on the income tax rule, you can commute part of your proceeds while investing in an annuity.
In case of death during the policy term, death benefits defined in the plan are payable to the nominee.