Exactly, PN knows little abut our SAM systems. The IN precise radar frequencies, pulse width and repition rates are not open information. That meant the PN might not be able to jam or spoof the system when the tie comes.
Even if India was invited, Iam sure they wont send any Warships but they may send a few personals to watch i think.
Btw, What type class ships did USN and PLAN send?. Also just for you guys to know, The SLNS Suranimala is a Israeli Saar class type Corvettee.
It seems both IN and PN uses Sea Kings Helicopters for their ASW roles.