01 December 2012
Form 3CA is for those who are required to do their accounts audited under statue other than Income tax Act and 3CB is for other who are required to do only Income tax audit.
Normally form 3CA is used in case of companies because they are required to do audit of accounts under companies act 1956.
But if the Financial year of the co. is other than Apr to mar then form 3cb is used.