Welcome to the forum! :)
Where is the window leaking?
Is it coming in through the inside, backing up in the track and spilling in? I'm assuming this window is a slider that opens, or similar.
If so, then removing the window and resealing will not cure it. A thorough cleaning of all places where water has access to should take care of it. These windows typically don't have drain holes as a house window. The frames are not hollow, therefore no need for internal drainage. They should have provisions for drainage from the inside of the track to the outside though, with perhaps a notch in the outside of the frame to allow it to run out.
Or is it coming in around the outside of the frame? If so, then yes, the window needs to be removed, thoroughly cleaned up and resealed.