If you still have swelling and bruising around the ankle RICE would be very beneficial. If, however, the swelling is gone won't so much.
To regain ROM in your ankle you have to start with the most basic movements. To start use a towel or a belt and pull your ankle into all of its range of motions. Thats toes up, down, in and out. Thats dorsi flexion, plantar flexion, inversion, and eversion for you anatomy freaks.
What you do is pull or push your ankle until you feel a restriction, then with gentle oscillations push past the restriction. Once you have increased your ROM some, you need to teach your muscles to actively move your ankle through that new ROM.