ravi,
Sorry that you are facing this issue.
Can you try “Refresh branches” option in the CVS Repository Exploring perspective ? Right click on cvs repository and click on Refresh branches.
Also, Can you please try connecting with the repository using another tool, such as Tortoise, to check whether you can see all branches using tortoise tool ?
If you are still facing any issues , can you please share your MyEclipse installation details from MyEclipse > Installation summary > Installation details ?
Let us know how it works for you.