THE Government will begin a clearance for the Hong Kong Housing Society's ''Six Streets'' redevelopment project in Tokwawan this morning. The project involves 118 four-storey to nine-storey post-war buildings. About 1,600 households and 180 commercial operators are affected. Possession of 66 shops has not yet been returned to the Government. An official said most of the 66 shop operators had received 75 per cent in provisional payments and had agreed to vacate their premises by March 31. The Government has paid about $26.1 million in ex gratia removal allowances to domestic households and commercial operators, and $42 million in statutory compensations to commercial operators.