Can you catch dialgia and palika in platinum

yes first u get the orb for diagla n palkia then go to celestic town talk to the elder in the house above the ruins when she gets done talking go to the spear pillar n forward until u see a blue poratal that's for diagla once u catch or defeat him go out and back in you will see a purple portal across where the other one was tats for palkia hope this helped
this is only works if you have seen ditto