GST on residential-cum-commerical Complex

If total area of Commercial units does not exceed 15% of total area of project then it will be treated as residential real estate project.

in your case area it approx 50% (all units are considered at same sq. ft.), hence your project can not be classified as residential rela estate project

If land is owned by you (JDA also included) then deduction of 1/3 is available to the rate of GST 

1. Commercial Building 18% GST Rate

2. Residential 1% or 5% (depending upon other conditions)

3. Maintain separate cost reports for commercial and residential and bifurcate your ITC

4. Currently no RCM on labour payment U/s. 9(4)

5. for both 80% cost from registered dealer need to be fulfilled

waiting for any additional suggestion from other member