Driving licence is issued for 20 years or 50 years of age whichever is earlier.
Medical certificate is required in case the applicant is more than 50 years of age.
You can renew it within 5 years from the date of its expiry. Penalty for late renewal is charged after the first 30 days of expiry. But remember that driving with an expired licence is an offence.
The Insurance Company will not provide the compensation and you will also be at fault in the Eyes of the Law.
Renewal of Driving License can not be applied before one month of the expiry period.