Well most of them said its a problem with the graphics card. I suspected this too coz just as solaris tries to load the GUI shell, the screen flickered 4 times (with a gap of 2-3 secs). I assume it was that solaris was tried to load the GUI shell but was unable to do so.
Another reasona may be that some installation files were missing. Thats because just before the disc-1 was going to end some errors showed up (missing files). May be these files were responible for proper working of the GUI shell and hence the problem.
This time I will configure the installing options manually and will post the results here