There is no law prescribing any formula for fixing a certain percentage as basic pay, and even the Minimum Wages Act does not interfere with the structure of salary as long as the wages you pay are not less than the minimum wages. It is entirely within the realm of the employer to fix the quantum of various components of the salary/wages, and no one can insist that P.F. contributions should be paid at least on minimum wages. However, the employer should adopt sound principles of wage fixation, considering the industry-cum-region formula, the degree of responsibilities, and the level of skills required to perform the job.
Basic Pay Guidelines
As per normal practice, Basic is usually fixed at 30% to 60% of the basic salary, with 30% being the lowest and 60% being the highest as a thumb rule. Just ensure that the basic + DA is equal to or more than the minimum wages applicable to your industry and location.
Regards,
Ashutosh Thakre