Summing up all the ways of getting a discount posted here by various learners in Edurev:
1) first and foremost, if you had downloaded the app from google app store then you could enter invitation code in the option given in the app from friends or various referral code posted here. (Or you can use KAK612)
2) Share your referral code to minimum 12 friends.
3) Watch Free Videos (10 mins daily streak also helps)
4) Attempt Free Tests. (giving correct answers lead to levelling up)
5) Read PDF notes(Daily limit of 5-10 pdf is there)
6) After doing all the above list for Day 1, check the Edurev infinity Upgrade option, you can see the current purchase price there. click "enter promo code " you will see the already existing promo code given by Edurev.
7) After attaining 600-700₹ Edurev money, you can easily get the lowest price available in edurev.
8) You can also click "Back" button from infinity upgrade page and they will ask you why you cannot purchase the infinity premium package now. you can choose financial difficulty option and they will send you promo code for 300₹+ discount. (I'd say currently ₹550 for a year till Dec 2021 and ₹650 for 2 year till Dec 2022 and ₹699 for 2 year till May 1, 2023 is the Best Deal given by Edurev)
That's pretty much about it!
Hope it helps. thanks for reading!