Yes, Samale Sales Reward Coins will expire after 365 Days (1 Year).

When Reward Coins will be credited in my account?
A. RewardCoins will be credited to your account after the return period is over for all the items in the order.

For every Rs.100 spent on a Samale Sales order, You can earn 4 RewardCoins. You can earn maximum of 100 RewardCoins per order.