Based on the set community and asset type, you can use the RAMAsset.getAllAvailableCategorySchemas() and RAMAsset.getAvailableCategorySchema(String schemaName) methods to fetch the full schema definitions of all the category schemas that are available to an asset.
//Fetch Category Schema by Name
RAMCategorySchema categorySchema = newAsset.getAvailableCategorySchema("My Category Schema");
//Fetch All Category Schemas
RAMCategorySchema[] schemas = newAsset.getAllAvailableCategorySchemas();