please ask the seller to obtain society NOC for sale of the car park space to you
the flat and the 2 car parks will be having combined share certificate and NOT separate share certificates
that is, the car park spaces are attached to the flat which is in turn attached to the society shares under a single share certificate
so if one of the premises forming part of the combined premises of flat and two parkings are sought to be separated by the society member by selling one of his car park space to you, then obviously this transaction will require NOC of society