I had been reading about using XBOX Gold codes to recharge upto 3 years and then activating the trial which converts your gold subscription to ultimate at 1:1 ratio. But was not sure how to do it in India as we can't buy codes online from resellers like Amazon, Flipkart etc. But i found a way around it by gifting the Gold codes to myself and redeeming those to add upto 3 years (36 months) to Gold plan. By gifting you get 6 months for Rs 1,238 (Rs 1,049 + 18%) compared to subscription per month Rs. 577 (489 + 18%). As a gift you get the same for Rs. 206 compared to Rs. 577 per month subscription. Its ridiculous really! You can do this to get 6+3 upto 36+3 months depending on your choice.
IMPORTANT: You should not have activated the Rs. 50 trial of 3 months for Ultimate. This only works before you have activated the trial and don't have an active Ultimate subscription already. If you do this with Ultimate sub already you will get reduced ratio from your gold codes.
So here the the steps to get upto 36 months of Gamepass Ultimate:
You need to make/have Microsoft account that you want to use for Gamepass and/or use with Xbox: https://account.microsoft.com/account
Visit XBOX Gold webpage: https://www.microsoft.com/en-in/p/xbox-live-gold/CFQ7TTC0K5DJ/000C?activetab=pivot:gamesanddealstab
Select 'Buy as Gift" as shown:
Complete the process by emailing yourself the code and making the payment.
Now you can do this 5 more times (for total 6) to get upto 36 months Gold subscription. Upto you how many months for Ultimate you want to get for this price. The maximum is 36 months.
Go to: https://account.microsoft.com/billing/orders/ Here you can see all your purchases. For each gift you bought you can view the gift code like this:
Go to: https://redeem.microsoft.com/ and redeem each of the codes you bought.
Now you can convert all of those months to Gamepass Ultimate.
Select like below to activate 3 month Ultimate trial for Rs. 50. You can also do this from XBOX app on PC or from XBOX console (can't test as i dont have it):
Complete the process and make the payment. Now you can see this work in your subscriptions: https://account.microsoft.com/services/
Tip: Turn off recurring billing so you don't get surprised with charges whenever your subscription ends. Click manage from the pic above and then do this:
Congrats you got upto 3 years of Gamepass Ultimate for Rs. 206/month compared to Rs. 805/month on top of the 3 months for Rs. 50.