The services provided by you fall under the category of job work by virtue of the definition of job work provided under Section 2 (68) of the CGST Act, 2017. The rate for job work in relation to trouser, which is a wearing apparel, is 18%.
(FAQ-8 TEXTILES)
Comments: In GST Council meeting dated 05-08-2017 and Notification dated 22-08-2017, all types of Job work for textiles has been taxed at 5%