498,

As per Muslim Law prevailing in India consent of first wife is taken for second marriage though Islam allows a Muslim to marry for four times.

Secondly if no consent taken then first wife may jolly well establish S. 498a IPC which is secular in nature as "mental cruelties" to her!

Thirdly if your brother is a Govt. servant then did he took permission for second marriage and/or informed his Authorities of his second marriage without divorce of first one?

This is asked here bze he may face again some Departmental enquiry though his religion permits him for four marriages but when S. 498a IPC pending and he being Govt. employee and due to which (I mean here earlier S. 498a r/w he going to jail probably for more than 24 hrs.) he was suspended then he / his family ought to have taken caution for his second marriage due to peculiar nature of criminal complaint (still un-decided) still pending against him.

Thus, he needs more Chamber guidance (legal) is my view.