22 October 2013
There is no specific time limit as such prescribed by icai ...you should regoister atleast 9 months before your attempt and must complete 2.5 years articleship.
I want to clarify that there is no time gap is specified for final registration. You should have a valid final registration number at the time of filing of Final examination form with Institute.
As per Regulation 50 of the CA Regulations, 1988, a student will be eligible to appear in Final Exam, after completing of 30 months (2 Years and 6 months) of article ship.