If you are not paying any dearness allowance which will vary according to cost of living index, it is always good if the basic salary is equal to the sum of basic plus DA as per notified minimum wages. Moreover, there should be increase in the basic pay considering the fact that salary means Basic salary and salary is increased to compensate increase in the cost of living and to reward the performance of the employee. You can put the amount above the notified minimum wages under any head. This is the safest way of salary structuring. Remember that there is no legal sanctity for your bifurcation of salary with 30% of the gross salary only on basic salary.