XBee S1 is using CMOS logic instead of TTL logic, hence MAX3232 have to be used instead of MAX232.

i have made the whole circuit of xbee serial explorer by using max3232 with (DIN, DOUT, RTS, DTR, CTS, Vcc and GND). connections but X-CTU is not detecting the Xbee module and i have checked all the connections so many times.
can any body tell me that what’s the possible reason???

Remember that the XBee creators likes old DCE terms, so CTS is an output, not an input.

If your connections match the spec: http://ftp1.digi.com/support/documentation/30010681-03_A_XBIB-R-DEV_scm.pdf
Then you could always double check your computers settings and try a recovery just to make sure your XBee is happy.
Optimizing USB to Serial Port Settings
Xbee Recovery

If you are really lost you could always post up a picture of your system.

I am assuming you are using all the pins you listed in your question. Try using just pins 2, 3, and 5 (DIN, DOUT, GND) which are the pins used to transmit and receive data, and ground.

I don’t know what you are trying to connect to, but maybe some of the handshaking used with the other pins are not being met. I would review some of these requirements with the device you are trying to reach.

It’s been a while since I have studied the various pins used in serial communication, but to bypass some of the handshaking I would pull these pins high (3.3 or 5v). However, please research these options before trying them.