@ Binyami...

candidates of CSS prefer to be PSP, DMG, FSP and in most cases customs is also very charming for them. but those candidates who fall in Information, , Railways, Postal, they definitely like to DDO (R) rather than in this group. (In current PCS several seniors of information group have succeeded and they will leave their 18 grade to join as DDO). In most of cases candidates of PAAS, MLCG, CTG, and Income tax also prefer to join as DDO (R), however sometimes the nature and priorities of a candidate also decide which way to go. But one thing is sure. DDO Revenue is a DMG group and currently second highest in terms of choice of the candidates, first is Police service.

Note: this is my personal view so any one can differ with my point of view.