casual taxpayer registration

my work is to went different places and sale handicraft item in trade fair at different places, also I don't have any office for this trade, shops in trade fairs are allotted at that time only ( first come first serve )..
how can I take registration and deposit tax .
as per act , casual dealer has to deposit tax on assumption basis before taking registration, but how can I deposit tax without being registered .....!!


suggest me solution!!