often changing audit firms..max how many times

their is no rule regarding max. no. of firms u can change in ur article ship duration.........

regarding second query.....u hve to submit form no.109 with the institute and get a fresh articleship form filled with the new firm giving them the form 109,,,,,,,,,

Dont change many firms it creates a negative impression

I think Ashish and Darsh*t both ar correct.