I want get my older passport

Although your query is not clear, here is the following information:
If your old passport is with the employer, you can file a complaint with the Ministry of Human Resources and Emiratisation against the employer.
In order to return your passport.
The employer will be called in order to force him to return your passport.
Finally,,,
If your query is related to something else, please clarify, so that we can respond properly.