This is the most common reason people come to the office and the hardest thing to write about honestly.
What the council holds is a record: which plots were allocated when, to whom, with what measurements, and what has been built on them. That record is often the oldest paper anybody has about a piece of land here, and it is worth coming to read.
What the council does not do is decide who owns land, settle a boundary between two families, or overturn what a previous allocation said. Those are decided by the office that holds that authority. The council receives applications, checks that the paperwork is complete, adds what its own record shows, and forwards the file with a covering letter.
So the useful thing to do is come to the desk with whatever paper you have, including the old ones, and ask what the council's record says. That conversation takes twenty minutes and it has saved people a year of writing to the wrong place.
Nothing the office says is a ruling, and we will not put a view about ownership in writing.