Please advise

You can make a representation in writing to your dpartment head and request to consider your promotion too at par with your colleague.

If the rules permit then the authorities may accept your representation, if not then you cannot do anything about it.

You should have taken up the issue when he was promoted to level 4 at that time itself instead of crying now. 

The government policy cannot be changed  at somebody's whims.

I have represented the same but they Rejected stating that you were at level 3 when I absorbed in NCDC. My coppenlist was at level4 that's why his seniority was reckoned from date same or equivalent grade in parent department (para 18 of dopt guidelines) whis is under,:

The seniorty of an officer absorbed after being on deputation or absorbed directly without being on deputation, if he has been already the same or equivalent grade on regular basis in his parents department, is determined from the date he has been holding the post on deputation or the date from which he has been appointed on regular basis to the same or equivalent grade in his parent department.

But the criteria of same or equivalent grade as per dopt and cat judgement is determined by the following

1. Nature of duties

2.job responsibility and power

3.Minimum.qualification

4.Pay level

Court judgement state that if first three conditions are similar then slight difference in  pay would not make any difference. In the approval of my coppenlist nowhere these criteria were considered. Just in behalf of pay level 4 approval was given. In case of me just behalf of pay level 3 my plea was turn down.

Comparative study of all post is as undeR

                                             My self.                                      Coppenlist.                        NCDC

POST.                                Lab assistant.                             Sr. Lab assistant.               Lab assistant 

Nature of duties.             Technical to assist in.           Similar as of myself.         Technical to assist in the                                                                                                                                                   testing of biological sample eg blood

                                            The testing of food sample 

Job responsibilities and-    group c post, assist in testing.    Similar as of my self.    Group c, assistant in testing                                                                                                                                                       of blood sample 

                                                 of food sample 

power

Minimum qualification.       12 th science                                   12 th science+ 5 yr on post of            B.Sc  science 

                                                                                                            Lab assistant, 100,% promotional 

Pay scal.                                  Level 3.                                               Level 4.                                                      Level 4

Now, it is to state that pay scale is not decisive criteria, cat judgement state that if ist three criteria i.e. nature, job responsibilities and power, minimum qualification are similar, slight difference in pay scale would not make any difference. Now you are requested to advice for the same. In the approval first three conditions were obviated from consideration.