Mishra, You should communicate with the client to make sure client is happy with the project work and will give TOP feedback And next you should end the contract on Upwork at your earliest.
Several months have passed since you received a payment. So Upwork system will take it negatively and you may get a negative impact on your job success score.
Upwork Premium Talent Cloud® Specialist
Please ask your client to close the contract, and if they fail to respond to your request, close the contract yourself. Note that inactive open contracts can affect your score negatively after a prolonged period of time. To avoid this, communicate with your clients when submitting the final product and ask them to end your contract if they don't have more work for you at the moment.