To use your Sky Remote with your Seiki TV you will need to ensure that your remote is Rev 10 or later. You can check this my removing the battery cover and you should find a sticker showing a Rev number. In the photo below, the remote is a Rev 9F so will not work with a Seiki television.
The codes allocated by Sky for Seiki TVs are 2992 and 3992
For instructions on how to set up the remote, please check the Sky website here