Q:

how can server send its multicast address and port number in android?

how can server send its multicast address and port number to another server in android?
Such that my client can join the group of the corresponding multicast address

A:

Multicast addresses are usually hard wired in advance. Otherwise you get into an infinite regress: you could multicast it, but where to? There are dynamic multicast address protocols in existence. I suggest you look them up.

