Can i resume smoking after 6 month of healing time for fracture on the midshaft femur bone? or should i hold it for at least a year?

6 months: Can turn into a year and then for a lifetime. Any doctor who tells you or encourages you to do so should hold that advise. You have not been smoking for 6 months. The withdrawal from nicotine is gone, only the behavioral problem of "being used to" you have to contend with. Remember, smoking can still cause avascular necrosis of the femoral head and other bad things. I hope you stop smoking.