Size of Data packet per Wireless Transmission


My work has been stuck due to a confusion about data packet bytes.

From some resources I have come to know that maximum size of data packet for communication per wireless will be 256 bytes but still not sure.

Data sheet shows , by frame with length of 16-bit that the data packet with max size can be approximately 65535 bytes or 8190 bits.

I am using XBee with Arduino DUE.

Kindly make it confirm.

Thanks in advance

What product are you working with?