Rhea, there are 2 Categories under which you can avail Uttarakhand State domicile. According to the official brochure available at: http://www.hnbumuexams.com/UKNEETUG19/InformationBrochure.pdf?_=636973383931679738,

1. A Candidate who is domicile/permanent resident of Uttarakhand and has studied his/her 10th and 12th in the State of Uttarakhand is eligible for State Quota of Uttarakhand.

2. A Candidate who is not domicile/permanent resident of Uttarakhand and has studied his/her 10th and 12th in the State of Uttarakhand is eligible for State Quota of Uttarakhand. But will not be eligible fore State reservations.

Now as a resident of Kerala, you are eligible for its State Quota and by the virtue of studying your 10th and 12th in Dehradun, you are eligible for Uttarakhand State Eligibility too.