From where dows solenoid attracts a magnet or some other magnetic substance ??????????

a solenoid when a electricity flows through its windings, becomes an electromagnet, this magnetic force is utilised to operate relays which allow large amounts of current to flow through a set of contacts, which otherwise would require huge manual switching. like any other magnet your iron fillings would radiate from the top and bottom of the solenoid when power is switched on.