Hello Abhaykumar Mehta,
Thanks for your question.
If you remove the last owner role, you lose the ability to manage the subscription. However, if you have the Global Administrator role in the Entra tenant associated with that subscription you can elevate it.
If this is not possible, you can further proceed to contact support to assist you via the global service numbers:
https://support.microsoft.com/en-us/topic/customer-service-phone-numbers-c0389ade-5640-e588-8b0e-28de8afeb3f2
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola