What would be the best tuning for my 6 string guitar for heavy metal?

B flat

Drop C or Drop D

Keep the normal tunining on all your strings except tune your low E DOWN to a C or a D. Possibly a flat would sound pretty good.

you should have standered tuning

and you should also give me 10 points

There’s no best tuning, per say, it’s all about the tone you’re trying to achieve.It would have been easier to perhaps list some bands you like. Some bands get an absolutely crushing tone from standard tuning, others use 8 strings tuned to a low F#, and so on.

Drop C (C G C F A D) seems popular nowadays, as it has the nice low end and the easy chord shaping that you get with ‘dropped’ tunings.

Personally, I use 7 string guitars, tuned down half a step (Bb, Eb, Ab, Db, Gb, Bb, Eb), and sometimes i’ll drop the Bb to an Ab. I have a tone that is very clear though, so I get very dark and brutal riffs but it’s still very articulate and defined.

Experiment man, jam with some of your favourite bands in their tunings, see what suits you best!