The optional LIMIT clause allows you to specify the maximum number of rows returned in the text query, up to 200. If unspecified, then the default is 200, which is the largest number of rows that can be returned.
You can set limits on individual objects, or on an entire query. Setting individual object limits allows you to prevent results from a single object using up the maximum query limit before other objects are returned. For example, if you issue the following query, at most 20 account records can be returned, and the remaining number of records can be contacts.
FIND {test} RETURNING Account(id LIMIT 20), Contact LIMIT 100
Object limits are evaluated in the order they are included in the query, and the maximum query limit is adjusted after each object is processed. For example, if only seven accounts match the query string above, then at most 93 contact records can be returned. Likewise, if the following query returns 15 accounts and 30 contacts, then only 55 opportunities can be returned, regardless of the Opportunity object's limit of 75:
FIND {test} RETURNING Account(id LIMIT 20), Contact, Opportunity(id LIMIT 75) LIMIT 100
If you specify a limit of 0, no records are returned for that object.