thanks for giving me your precious time.
and i checked all the connectors and removed carbon from all the switches but still results are same.
Are u sure about all the contact points and connectors?
If then, Set the idle speed to 4K rpm by adjusting the idle screw (the screw with the spring) Make a test lamp with a 12V 35W HL bulb and connect any of the beam points with a pair of wires and connect one of the wire to any bolt which is on the chassis of the bike to get the ground and connect the other wire to the yellow wire (IIRC) from the RR socket (lighting supply) without disconnecting the RR and start the bike and see the brightness.
Check the voltages on both yellow wires before doing this to identify the RR out wire else u may blow the test lamp in no time. Regulated wire will be supplying constant 13-13.5V whereas on the other yellow wire will be around 70-90V. If the bulb glows to its full brightness this time without any issues, there's a loose contact some where in the wire loom, connector pins, HL switch etc.
Check one by one:
Repeat the above test at the yellow wire (source point) on the RH side HL main switch, if its fine;
Open the LH side HL switch and test it on the yellow wire coming from the main switch,
Next trace the wire at the Hi/low switch common point,
repeat the test till u find the cause to the bulb.
If the above test failed at the RR out, Check the AC voltage from the yellow/red striped wire (IIRC) from the stator coil without disconnecting by the help of a DMM probes, (U can check this at the stock RR end also) if the voltage varies irregularly on constant rpm, the problem is within the coil side. U need to open the stator cover and check for any dry solder/wire cuts from the light coils etc.