You be active at tripoto app, u will earn credit.
Tripoto sells vacation package,if you book that vacation package then some percentage of cost will be redeemable through your credit.
tripoto change redeemable percentage time to time.
Credits basically helps you to cut down some amount from the travel packages you choose from tripoto travel options. it's like some points which you can redeem on purchase of packages. for example there is a tripoto package for 5 day trek at shimla costing you around 10000 per person. You have 400 credits, and by using these you might get it for less. for example 8 k Or something.