Though a General Circular No. 50/ 2011 dated 25.07.2011 is notified wherein a simplified process is going to be introduced  with new e-forms, still, till Dec, 2011, the old process is to be followed :-

Therefore, in case, company wants to shift the registered office from one state to another state, it needs to file following forms to give effect to such change. These forms are:

1) Form 23 with special resolution
2) File petition with CLB and intimate ROC in Form 61 
3) Form 21 (Notice of the court or the company law board order)
4) Form 18 ( Notice of situation or change of situation of registered office)

It takes around  2-3 months for above work.