As good is paytm app, that much worse is paytmmall. First of all paytm mall shows cashback offers on each and every product, soon you get realise that all these offers are only for the first time customers. Then also all those cashbacks are clearly written as cashback upto ₹50 that means they can provide a cashback of ₹0to₹50. Which in general is very low.
Coming to the next point whatever item you will need to purchase will be delivered in not less that 6-7 days. Also if you compare price of the products on different online shopping app like flipkart and amazon. You will get realise that it is much more of the price on other websites. Even discounted and cashback substracted sum will be more than real price on other websites.
Now when you will try using any promocode a popup box will say you are not eligible to use that promocode for some reasons. This happens each and every time.
So my recommendation is dont use paytm mall in search of cashbacks where you can use trusted and reliable websites with a very good service.