okay then where can i find one 600 mil?

Here:

http://www.reichelt.de

here:

http://www.buerklin.de

and here:

http://www.conrad.de

for instance. All do have this 6264 in wide DIP28 package (600mil)!

But even if you would not be able to get it, then you can also use any other 62256 SRAM complying with JEDEC pinout, PROVIDED THAT pin 2 of 6264 (CS2) is not used for address decoding, but is permanently connected to Vcc. THEN, just connect pin 1 of socket (A14 of 62256) to ground or Vcc.

If pin 26 of 6264 (CS2) is used differently, which can be the case for instance if 6264 is used as battery powered nonvolatile SRAM, then, additional analysis have to be made to check the compatibility.

Kai