I want to make a 100W high power LED headlight for bike, but the problem is that LED releases a lot of heat, and I'm using a 150W boost converter to convert 12V to 30V ( minimum operating voltage of 100W LED), to reduce the heat I have to reduce the current to 1A(from battery it is 6A), and for that I'm thinking to use l7812 which is a 12V linear voltage regulator but, it will not be able to handle that much amount of current I think so. Can I ue linear voltage regulator or sothing else? I'm experienced with printing PCBs using toner transfer and also with soldering. I'm confused what to do please suggest me a solution LED specs- 100W 32-35V 3000mA Genesis's 30Mil
When you measured your LED drawing 6 A from a 30 V supply (if I understand right), that was 180 W. Your LED would not last long at that power. You do need a way to limit the current.
Best would be to find a 100 W current-regulated boost LED driver instead of a voltage-regulated boost regulator. Then you don't need any other components.
If you want to use a linear regulator, get a low-dropout regulator configured as a current and not as a voltage regulator. Then set the boost voltage as close to the LED voltage as the regulator dropout voltage will allow. If it's only one or two volts and 1 A, then only a couple Watts will be dissipated in the linear regulator, which is OK with an appropriate heatsink.
A word of caution about mounting a 100 W LED on a bike (I assume you mean bicycle): you really want to make sure that you have appropriate optics and diffusers in front of that LED so that the light comes from a large surface area (like car headlights) and not from a very small, 1 cm\$^2\$ point source. Otherwise you will badly blind anyone coming towards you, maybe even damaging their retinas, possibly causing an accident which may also involve you.