Is someone chose physics, chemistry, maths in 12th , what will be better Engineering or Law for future?
These subjects have nothing to do with law, so a better choice would be Engineering, But you can also choose law but then These subjects are of no use, better if you had taken Humanities if you are more interested in Laws. But with this subjects, it is most justified if someone takes Engineering.
From future point of view both are equally good at their place.All you need to do is understand that what is good for you and in what you are good at. You should choose what really motivates and drives you so that you could enjoy enjoy what study you will persue and what job you will do.
Take some time and think on that.
I hope this helps.