How to send transform.position and transform.rotation values to Google multiplayer server?

This is for a multilayer game where i need to send the postion and rotation values for the server and get it back from there again.Google only allows sending through bytes. This is what i am trying.

           float aa; 
             float bb; 
             float cc;
             
             
             byte[] xx =new byte[5]; 
             byte[] yy =new byte[5]; 
             byte[] zz =new byte[5];
             
             void Update() { 
         
             aa=transform.postion.x; 
             bb=transform.postion.y; 
             cc = transform.postion.z;
             
             xx = System.BitConverter.GetBytes (aa); 
             yy = System.BitConverter.GetBytes(bb); 
             zz = System.BitConverter.GetBytes(cc);
     
     PlayGamesPlatform.Instance.RealTime..SendMessageToAll(false,xx);
  PlayGamesPlatform.Instance.RealTime..SendMessageToAll(false,xx); 
  PlayGamesPlatform.Instance.RealTime.SendMessageToAll(false,zz);
             
             } 

Now i don't know how to check what data i am receiving. Generally, accrording to Googles examples its done like this:

 byte[] temp = new byte[1];
 temp=(byte)'R';
 
 public void OnRealTimeMessageReceived(bool isReliable, string senderId, byte[] data) {
  if(data[0]==(byte)'R' )
  {
   
   float xyz = data[0];
  }
  }

But in this case i don't have a character at the start of the byte array. How to send Quaternion values beats me. Thanks in advance.