Working for client with layers like this
Client -> prime vendor -> company b -> company A

Working with company A without any problem for last 2 years continuosly. Planning to change Company B , since paywise it is good and well established since 2001. I have my marrige in may and may14 th i'm travelling to my country.

Company B will do transfer based on client project.
client letter is not saying project time frame.

1. If transfer denied , can i go for extension with company A.
What is the best time to tell company A that i donot work with them? should i join company B right away and tell company A,
not working with them?

2. How to proceed with company b h1 transfer and employer
and employee relation ship while on subcontract?