Avoid sitting Cross legged. Contrast Fomentation (Hot and Cold). Quadriceps strengthening exercises-

You can start walk and ball exercise

Yes you can. But accessing the strength and exercising consult a physiotherapist and only under monitoring right now. Thanks

If you are allowed to walk with full weight bearing ie. With walking stick or without it, you can start with walking, static cycling, swimming and strengthening exercise with light resistance band. The duration of exercises would be as per your stamina. Start slowly and then gradually increase. Avoid jumping, jogging or high impact exercises. Include them when you have enough strength in your bones which your orthopedic will tell you later. Avoid or take rest or reduce the exercises if any exercise increases your pain Thanks.