Section 28A(7)(b) in The Rajasthan Accounts Service Rules, 1954
(b)in a Service or Groups or Sections thereunder, where there are three scales e.g. junior scale, senior scale and selection scale and there are two promotions then promotion shall be as under:(i)first promotion on the basis of seniority-cum merit;(ii)second promotion on the basis of seniority-cum-merit and merit in the proportion of 50:50.