If you have a scar on your scalp, it is not possible to regrow your hair. But there are ways to get the hair back such as with hair implants. You can make the scar invisible by undergoing this treatment as the hair will cover them perfectly. The hair will get its own root after sometime and you can start styling them as usual. You must visit a hair specialist to get your hair implants. There are also ways to make your hair implants look completely natural which is known as micrografting. This treatment can be costly, so try to consult the hair specialist before proceeding with this it.
You must ready to face the treatment after consulting the hair specialist as they will give you the appointment for starting the process. The scalp will be injected with a solution where you have the scar as it will reduce the pain during the process. The hair specialist will do the surgery by taking the small patches with hair around the scar to replace them with new hair follicles. You have to leave the hair for at least two weeks before styling it normally as you would do. Avoid touching the scalp with pressure during this period as it can affect the new hair follicles. There is no need to follow any particular method for maintaining the new hair as you can treat them with the rest of your hair over the head.