Hope this isn't a con how do I register my 6 months extra free ?

Entirely depends on the whims of the company. I guess your serial # of tv is off that extra warranty list.

Who provides the extra 6 months? Go to them directly for that provision. If it is a credit card the extension is automatic.

And brand - model is ???

Type "Sharp warranty service" on your search engine or Contact the place you purchased it from and they should be able to help.

taken from the skymedia webpage

In order to get 6 months free guarantee, you must register your product within 7 days of purchasing it.

With great difficulty!
I have suggested to all I have seen that as the TV was sold by a retailer, advertised as having an extra 6 months warranty that is not within reach as there is a missing link on Sky's web site, there should be a complaint made to the retailer.
I hope you will complain also.

And so does everyone else. The link doesn't work.
Complain to Tesco.

want to register my new tv for 6 months extra free warrenty, help

There apears to be an error with the address.
Try this address;
http://www.skymediauk.co.uk/manufacturers_guarantee_registration.php

I hope that helps.

I have just got my new Technika tv and it has got free 6 mouth extra guarantee i have gone on to the webpage but cant see how to get 6 mouths extra free i can find 3 mouths free so would tell me how to get it please