is this compatible with shimano HG 12-25 cassette?
12-25 seems like a cassette that was on a road bike. Most 9-speed road bikes can not accept cassette cogs larger than 27t. If you are adapting a mountain bike derailleur to a road bike, then you can run a 11-32 or 11-34 cassette. Otherwise we would need to track down a more appropriate cassette with a road bike gear range. The Sunrace CS-R91 would be a better choice for a road bike. Here is the link: https://www.thebikesmiths.com/collections/cassette-9-speed/products/csr91 Thanks.