@Neerja Do not know about Brampton, but may be similar to Toronto.
In Toronto its very variable. When I went a month ago for OCI, atleast 60 walk-ins were let in going by the token numbers, and what the security said. Even those came in at 11am got in by 1pm. Last week I heard some days only 20 were taken and a majority turned away. Depends on how busy the day is and how many appointment no-shows. Brampton may be similar.
BTW, did you get Ack for the 13th Oct OCI application?