After the CPI-IW (2016=100) series replaced the CPI-IW (2001=100) series effective September 20, All India index for the month of September, 2020 was initially reported by M/o Labour & Employment as 118.
Dearness Allowance for RBI employees and also for other banks’ employees was calculated and paid taking into account the above figure -118 .
Accordingly increase of 4.30% (43 slabs) for the quarter Nov 20-Jan 21 was communicated to offices by Central Office.
However, while reporting figures for for the month of October, 2020 (released on 27th November 20), the M/o Labour & Employment revised the earlier figure of 118 for the month September 20 to 118.1 . Consequently, the average CPI comes to 7716.13 and the number of DA slabs to 819 (7716 – 4440= 3276/4= 819 Slabs). Since the last quarterly Payment of DA was at 775 Slabs, there is an increase of 44 DA slabs. The total payable DA works out to 81.9% of pay for the quarter November 20 to January 2021. 

IBA and RBI , having taken note of the revised figures, issued circulars for payment of 44 slabs instead of earlier 43 slabs to the employees.

The pensioners are entitled to dearness relief from Feb 21 on the basis of quarterly average for the months of October, November, and December 20. The figure for the October 20 is 119.50 and when converted to base year 2001=100, comes to 7855.76. Assuming this as the quarterly average, the increase of 79 slabs is already there and the arrest of rising inflation is most unlikely during the quarter.