If I co-sign for my parents to get an apartment, can I be taken off upon lease renewal?

It is completely up to the landlord to determine after the initial lease. But if your parents lease simply reverted to a month to month tenancy after their original lease term, your liability would be limited to a months rent. Being a co-signor for your parents should not effect you in the slightest bit as long as they pay the rent. It is very rare that a landlord reports to a credit agency, thus your guarantee of the lease will not effect your credit at all. So being "stuck" isn't really applicable.