Download the ns and patch from the packages given below !!!!!!
http://sourceforge.net/projects/nsnam/ ( Fro NS)
http://sourceforge.net/projects/um-olsr/ ( For UM OLSR 0.8.8)
http://jauu.net/var/misc/exchange/um-olsr-current-ns2.33-rc4.patch ( For OLSR Current Patch)
Now go for the following in the console.....
$ tar zxvf ns-allinone-2.33.tar.gz
$ cd ns-allinone-2.33/ns-2.33
$ tar zxvf ../../um-olsr-0.8.8.tgz
$ ln -s ./um-olsr-0.8.8 ./olsr
$ cp um-olsr-current-ns2.33-rc4.patch olsr/.
$ patch -p1 < olsr/um-olsr-current-ns2.33-rc4.patch
$ cd ../
$ ./install
