They are different. Keep in touch means that they are already in contact and this is continuing. Get in touch means that contact is resumed after a break or made for the first time

Keep in touch means to ask someone to keep in regular contact with you. eg. Nice to see you again, keep in touch. Get in touch means to make contact directly. eg: Mariya, get in touch with the office manager today/tomorrow. I hope my suggestions help. Only small tweaks needed:) If you'd like to practice speaking, I'd be happy to help you develop a study plan. Feel free to look at my teaching profile and class offerings and send me a message if you think I may be able to help you

'Keep in touch' is something you do with friends or family you no longer see automatically. So friends you no longer work with, or family who have moved away. 'Get in touch' is usually someone you don't know, but could be used instead of 'get back in touch' which would be contacting someone you had 'lost touch' with, someone you had not been in contact with for a while.