How to expose multiple routers within one net

Hello,

here is the scenario:
I have a main router (also managing home phone system voice "C-Beyond unit") which has three routers installed directly under it:
Main Router IP: 10.0.1.1
The three routers under the Main Router are Crestron IP: 10.0.1.200, MovieServer IP: 10.0.1.100, MusicServer IP: 10.0.1.150, and are setup this way to allow three independent routers to manage their traffic and resources on their own infrastructure.

Internal Router LAN IPs are as follows:
Cresetron Sub Node: 192.168.200.x
MovieServer Sub Node: 192.168.100.x
MusicServer Sub Node: 192.168.150.x

What I need to do is to expose the Crestron router to the Music Router so I can control the MusicServer operation from the Crestron Sub Node over the TCP/IP

How do I do this?

I think all I have to do it to set my IP Mask to 255.255.0.0 and than I will be able to directly access the units in MusicServer Sub Node from the Crestron Sub Node.

Farther-more, should I change the 192.168.x.x to 172.30.x.x?

Your advice is appreciated.
G.