Some sinks are hung with carriers in walland arms are used on finish to hold up Lav. Some hangers work on other sinks but not many, if it is cast iron I saw brackets knocked out for sink and hung on wall. Get the name of sink and search on the net. the box stores carry a few different ones try them. When we rough in for wall hung sink we put in a 2×8 between studs to support it and on finish use 2-1/2″ screws and install hanger. If you got a Vitious china sink with holes on each side thats for a carrier in wall, but you can also hang it with hanger, that would be a easy hanger to get. You can hang them with anchors are togels which I do not Advise. Cut out drywall and install wood and patch wall back. Let me know.
Art retired plbg