The Employees' Provident Fund (EPF) is governed by the Employees' Provident Fund and Miscellaneous Provisions Act, 1952. According to this Act, an employer is mandated to contribute to the EPF on the basis of the basic wages, dearness allowance, and retaining allowance, if any. The statutory limit for such contribution is currently set at INR 15,000 per month. If an employee's salary (basic + dearness allowance) exceeds this amount, the employer is not legally obligated to make contributions exceeding the statutory limit. However, in practice, many employers choose to continue making contributions based on the actual salary in order to provide better benefits to their employees.
Regarding your question about whether you can reduce the EPF contribution to the statutory limit after it has been higher, the answer is yes, you can. Because the statutory limit is the legal requirement, any contribution above this limit is voluntary. Therefore, an employer can choose to reduce the contribution to the statutory limit at any time. However, it's important to communicate this change clearly to the employee and to ensure that it's done in compliance with any relevant employment contracts and company policies.
Finally, as for your question about whether this would be a violation of Section 12 of the EPF Act, the answer is no, it would not be a violation. Section 12 of the EPF Act prohibits employers from reducing the wages of an employee in order to evade their obligations under the Act. However, because the statutory limit is the legal requirement, reducing the EPF contribution to this limit would not constitute a reduction of wages, and therefore would not be a violation of this section of the Act.
I hope this helps clarify things for you. If you have any more questions, please don't hesitate to ask.