How to Read values of OBIS in C# in either XML or some format

i need finally in dictionary form but i can convert from xml

GXReplyData reply = new GXReplyData();

reply = PublicClientAAREAARQ(reply);
reply.Clear();
byte[][] readBlockType = GetOBISReadBlock(obis);

ReadDataBlock(readBlockType, reply);
Client.ParseAAREResponse(reply.Data);

here i am getting invalid tag error is there any other way i can read it, also please help in context of reading GXDLMSObjectCollection,

thanks in advance