Mechatronics engineering

Is it important to take mechanics with pure maths in A2 to pursue Mechatronics Engineering or it doesn't matter?

Have you looked at the entry requirements for Mechatronic type courses? Here is Loughborough for example
https://www.lboro.ac.uk/study/undergraduate/courses/robotics-mechatronics-control-engineering-beng/

I am aware of the requirements for the course, but I haven't found anything that talked about my question yet. They have mentioned that you must take maths and two science subjects, nothing in specific about maths.

That is because they don't mind. As long as you have some sort of maths. For what it is worth, I did maths with mechanics before doing electronic engineering at uni. The mechanics bit was interesting but I would have been better focusing on pure maths for university because most of the first and second year engineering maths units involved lots of integration and differentiation, something I hardly touched at A-level. If you are doing physics you may well touch the mechanics subjects from maths anyway.