@Abhishek Narvekar There are various quotas and limits applicable to the Azure OpenAI Service and the error that you are getting is related to the token limits which are defined at a regional level by model for all services in a subscription in the official docs.
Firstly, you could check the quota for your deployment in the Quotas Page to ensure your model is assigned the maximum available quota.
Next, you should implement retry policies in your code so that it can work around these rate limits.
And finally, if you are already exhausting all available quota, you could try requesting for more. Do note that due to overwhelming demand, requests are being accepted and will be filled in the order they are received.