Source - licindia.com -
Days Of Grace
Policy holders are expected to pay premium on due dates. a period is 15-30 days is allowed as grace to make payment of premium; such period is days of grace.
Reinstatement
The restoration of a lapsed policy to in-force status. Reinstatement can only occur after the expiration of the grace period. The company may require evidence of insurability (and, if health status has changed, deny reinstatement), and will always require payment of the total amount of past due premium.