If the statutory minimum wage is Rs 9743, then you can deduct and contribute 12% of it to PF. You cannot reduce the PF contributing salary to any amount less than this.
There is no best salary structure to save PF, but you can choose the ideal or optimum salary structure to reduce the tension of PF-related inspections and risks associated with it. That is, consider the salary of Rs 15000 for PF. If the statutory minimum wage is less than Rs 15000, then contribute PF based on that minimum wage.
Please consider employees as an asset and not a burden.