You will receive the funds in your primary bank account which is registered with Upstox.
While placing the withdrawal request, you can see the primary bank account name & last 4 digits of your bank account number- to which your amount will be credited.
Related Article:
How can I withdraw funds from my Upstox account?
Why has my withdrawal request been rejected?
How can I add funds to my Upstox account?
Why is my instant payout not credited to my bank account? (Deemed Success)?