Section 7(1)(a) in The Bihar Irrigation and Flood Protection, (Betterment Contribution) Rules, 1961
(a)by delivering or tendering a copy of the notice to the assessee personally or to his agent if he (the agent) is empowered to accept service of the notice on his behalf or, to any adult male member of his (the assessee's) family residing with him, if he himself cannot be found and has no agent empowered to accept service of the notice on his behalf;