Hi @Sanjay Kumar R (INFOSYS LIMITED) , welcome to Microsoft Q&A forum.
You can use below equivalent when using the Microsoft.Azure.Cosmos package:
DeleteDocumentAsync --> Container.DeleteItemAsync<T> Method
ReadDocumentAsync --> Container.ReadItemAsync<T> Method
UpsertDoumentAsync --> Container.UpsertItemAsync<T> Method
Please let us know if this is what you are looking for, or else we can discuss further on the same.