Would i be able to move my fingers if a tendon in my wrist was cut? my middle and ring finger have very limited range. is surgery needed?

Depends: Remember you have multiple tendons attached to your finger(s). So if one tendon is completely severed you will likely loss some motion but unlikely all motion. It's uncommon to severe a finger tendon without an obvious significant trauma, it's more likely that the tendon isn't able to slide appropriately along it's track, like in trigger finger. Seek the help of an orthopedic doctor.