I would like to implement skill based routing in Salesforce omnichannel. There is only 1 Queue where cases are assigned. From the queue the router should assign the tickets to the agents based on their skills other than capacity.
Currently it is not supported by Omni Channel and is listed in IdeaExchange Omni-Channel Skill Based Routing
You can vote for the ideas.
This is not possible as of now and I don't think Salesforce will release this considering it just offered Live Agent to shift from skill based to Omni-channel based routing https://releasenotes.docs.salesforce.com/en-us/spring17/release-notes/rn_live_agent_omnirouting.htm
What I would recommend instead is to create queues based on skills and assign to these queues based on various criteria. Assignment can happen within the queue based on omni channel.
This will be included in Spring '18 as a beta feature.