Spass rejection

Care to elaborate more? What do you mean by he had resume? Anyone can carry a resume and appear for an interview whilst here, there is no such rule that makes it an offence. I am sure there is more to it.

He took job resume while traveling by tourist visa .And also they saw the chat in whatsapp in which my bro had a chat about job profile and interview in my  brothers phone .

Was he denied entry before or after the S-Pass rejections because of adverse record?
A lawyer can probably not help with this, as the authorities can (at their sole discretion) ban anyone from entering Singapore for any reason they like. Your brother should better contact ICA (or MoM, if he thinks the problem lies with them) to ask how long the ban will last and whether anything could be done to shorten it.

During first visit adverse record issue is not in the place.He was denied entry before spass application.And also they are not telling why he is in adverse record asked him appeal through employer.Even after appealing they rejecting with adverse record without telling the reasons to the employer.

Appealing (or applying again) for a work pass at MoM cannot help against an adverse record elsewhere and is thus a waste of time.
As I wrote above, your brother should contact the relevant authority (most likely ICA) instead.