sixth pay for university teachers

it is known to us that in the sixth pay,basic pay is fixed based on the pay grade.The rules says that if the pay grade is 5400 the basic pay is 15600,if the pay grade is 6600 the basic pay is fixed at 18750,and if pay grade is 7600 then basic pay is fixed at 21900,if pay grade is 8700 then basic is fixed at 37300 and so on.Now the acadamic pay grades are 6000,7000,8000,9000,which is clearly not in the rules of the sixth pay commission rules as notified by the govt of India.As per the definition of pay grade in the sixth pay commission,if the pay grade is 6000 the basic pay should be fixed at Rs 17175.For the pay grade 7000, the basic pay should be at Rs 19970,and for pay grade 8000 the basic pay should be fixed at rs 27190.Now the total bsic pays at the pay grades of 6000,7000,8000 should be 23175,26970,35190 respectively.the main argument is if our pay grade is 6000,how can our basic pay will be fixed at 15600 rather it should be at 17175 and so on.since our pay grade is not defined in the definition of sixth pay of the govt of india.So some mathematical modeling should be applied.Let x denotes the pay grade and y denotes the basic pay to be fixed.by using the well known pay grades x=5400,6600,7600,8700 etc and basic pays y=15600,18750,21900,37300 etc.Using the principle of the least square,we can fit an appropriate curve in the x-y plane.one of the simpliest method is fixing them linearly piece wise.i.e. join pts (5400,15600) and (6600,18750);join pts (6600,18750) and (7600,21900) lastly join pts (7600,21900) and (8700,37300).From this graph if x=6000,7000,8000 then y=17175,19970,27190 respectively.Thus the total basic pays should be 23175,26970,35190 for the pay grades of 6000,7000,8000 respectively.We should keep in mind that in the sixth pay commission pay grades determine the position of the post.