Calculation of pension on the basis of average salary?

Sir, In July-17 I have completed 58 yrs. of service. Thus completed 11 years 8 months in present employer. 5 years pensionable service had been added to present account thorough scheme certificate. As come to know basic will be average of last five years salary. My last five years salary (Basic pay as there is no DA in our company) is as under:-
25750
24000
22250
20500
18750
Average salary will be Rs.22250/-
And pensionable salary will be 12 yrs. + 5 years = 17 years.
As heard if 2 additional years of services then it will be 19 yrs.
I am not clear whether pension will be calculated on the basis of average salary Rs.22250/- OR Rs.15000/-
Request concerned knowing person how pension will be calculated.
Regards,
B. Surya Rao
BHILAI

Dear B. Surya Rao,
If your contribution to pension fund is on ceiling salary, you will get pension up to 31.8.2014 on a salary of Rs. 6500 & w.e.f 01.09.2014 on Rs. 11316.67 (average of last 60 months i.e till 31.8.2014, 26 months with 6500 & w.e.f 1.9.2014, 34 months with Rs. 15000). As your Total service in PF is below 20 years, you are not eligible for 2 years weightage.
Abbas.P.S