A monthly CAS will have only those folios in which a financial transaction took place in a given month. Furthermore, a valid PAN should be provided for the folios. For example, if you have investments in 5 mutual funds (5 folios), but in the month of Dec 2021, you have made investments only in three folios. Therefore, your Jan 2022 report will consist of only three transactions (the folios in which transactions happened).