In case of job work, value of material will be included in aggregate turnover of principal for considering exemption available to small persons :
The supply of goods, after completion of job-work, by a registered job worker shall be treated as the supply of goods by the principal referred to in section 143, and the value of such goods shall not be included in the aggregate turnover of the registered job worker – Explanation (i) to section 22 of CGST Act.
Thus, in case of job work, value of material will be included in aggregate turnover of principal for considering exemption available to small persons (having turnover of 20/10 lakhs) and not in turnover of job worker.