There are some insurance policies that guarantee the amount of money you would receive upon maturity. Typically, this amount is a proportion of the sum assured such as a bonus or a guaranteed addition. Lets say bonus is Rs 50 per Rs 1000 of the sum assured and you have an insurance policy for a sum assured of Rs 100,000 then you earn a bonus of Rs 5,000 each year on the sum assured.
Other policies may offer you a guaranteed bonus as a percentage such as a guaranteed addition of 3.5% per annum on a compounded basis.