You need to programme the remote to control your TV.... Follow the instructions
HERE,
If your TV isn't listed on the above link then there is a more comprehensive and upto date list of remote codes on Sky interactive pages.
Press 'Interactive' on your Sky remote, then it's Sky Active > Help Centre > Set Up My Sky Remote
If all else fails and your TV isn't listed there either, then try the 'Step and Set' method of programming the remote, which will toggle through all the codes stored in the remote till you find one that works.
Instruction for 'Step and Set'
HERE (scroll down to 1.2)