Hi Arif,
You are back with a Arif style question again, This is not a place to discuss things other than 8051.
Anyways I wont disapoint you, I would personally recommend you an Aplab make oscilloscope[ Really great Quality ]. Go for a 20MHz one If you want a resonable cost scope[ Nice for working with MCS-51 12 cycle or 6 cycle controllers ]. If cost is not the main factor you can go ahead with higher frequency [100MHz] scopes. But Remember 100MHz good scope wont cost you less than Rs. 60,000/-. Beware of those cheap funny brand scopes, you can get one dirt cheap but in terms of quality they are shit. I purchased one 10MHz scope for 8,000/- some 2 months ago, It worked well for a month or so but now it no more works. Now I realise my mistake it would have been really worthy if I would have spent a little more money for some nice brand scope.

Regards,
Prahlad Purohit

DISCLAIMER : I am in no way related to Aplab.