That won't yield much because the gap between even a 100% increase in salary and the amount of bribes they collect is vast.
E.g. salary of an inspector could be, say INR 40k-50k per month but the bribes being collected typically would be millions of INR. Suppose an inspector has 15 people reporting to him who are collecting INR 200 from 300 people per day and the inspectors share in this is just 5%. Then the amount per month is 200 * 300 * 30 * 15 * .05 = INR 1350000. If I assume the salary to be 50k per month, this bribe amount is 27 times that. It is just not possible for the government to get the salary even in the same vicinity (just for kicks, Indian President's salary is about INR 500000 per month).