Roommate Moving Out for 3 Months and Trying to Sublet

My question involves landlord-tenant law in the State of: New York (Brooklyn)

We are month to month. Each roommate pays rent with an individual check. We want this roommate to move out for myriad reasons. The roommate is planning on leaving the country for 3 months and sticking us with a person of her choosing. Obviously this is not what we want as we would like to choose who we live with. The roommate was given 30 days notice to move out by us. The roommate is stating that they are not going to move out, eventhough they will not be living here. Can we legally evict the roommate?

If you are stating that you're all on the same lease and subletting is permitted (I believe NYC requires landlords to permit subletting), then you have no ability to evict your roommate. you do have the right to reasonably reject a replacement roommate, but if your rejection is unreasonable and your roommate stops paying rent odds are you would lose a court action to try to recover "his share". You and your fellow roommates can explore finding a replacement roommate of your own, but your unwanted roommate would have to cooperate - that is, agree to let this new person assume his rights and obligations under the lease, not try to assert rights as a tenant during the subtenancy and certainly not try to rent the room to yet another person.