We have to see if Mars is in a good placement. Nakshatra of mars, how many places away from 10th house it sits and the house of mars matters. Ketu alone can't derive any conclusion. But yes ketu in 10th may give initial struggles in settlement of the native. Frequent job change is evident. If mars is really well placed job change brings higher designation and better salary with improved workplace. If mars is making any connection with sun then multiple government jobs may be seen where the native cracks government job exams one after the other. But here Jupiter and 6th house should also be considered. The placement of ketu alone is very vague to make conclusions.