As much as possible; insofar as practicable; if possible.
なるたけ早く返信してください。
Please reply as soon as possible.
なるたけ低予算でプロジェクトを進めたい。
I want to carry out the project with as low a budget as possible.
体調が悪ければ、なるたけ無理をしないで休んでください。
If you're not feeling well, please rest and avoid pushing yourself as much as possible.