leave the groups of three cables together this is a loop in method to all other upstairs lights, connect your brown to the (black with red tape on it) connect your blue to the group of blacks this is neutral. you may have to connect the groups of 3 cables into a large terminal block.
When wiring a house some electricians used 2 core cable i.e. red to switch and use the black as switched live indicated with red tape (the one you need to connect the brown).
Oh always isolate electric before attempting any wiring.
hudde01
October 2011