Hello Anil,
I appreciate your patience and time. After careful review, it is feasible to use the same group for various lessons and give your students homework in Microsoft Teams.
To create a group assignment, navigate to your desired class team and select Assignments. Then, select Create > Assignment. Select the student dropdown under Assign to, and by default, All Students will be selected. Select Groups of students and choose whether you would like to create groups Manually or Randomly.
I also found some workarounds that you can also try but in need assistance from your admin or IT to enable it. You can delegate a task to particular class members based on the user. As a result, you can distribute it among the students in a specified group.
This must be done in your Active Directory or Office 365 User Admin account. I suggest to inform your admin to do this.
Here's the source: https://techcommunity.microsoft.com/t5/microsof...
This can also help you: https://support.microsoft.com/en-us/topic/creat...
I hope this helps! Let me know if you have any further questions.
Kind regards,
Jayzar
Note that I am not affiliated with Microsoft. In this community, I also assist other users by being a user myself.