Any condition regarding minimum term of articleship?

Is there something like minimum period of articleship which you are required to complete before taking your first transfer otherwise it'll be counted as nil period???i've heard it's six months but i dun believe that it's true...maybe you can help me regarding dat...as a matter of fact, i have cleared my pe-2 in may'07 and i started my articleship on 18th oct. n since my c.a. is screwing me really big time, i want to go for transfer and hence, i have completed only 4 months till now...