SO I noticed there is a cut on my tyre.
I was wondering whether there is some way I could repair it since those tyres were only replaced a few months ago. If so, what are the best ways to go about repairing it?
Or is it so serious, that it needs to get replacement?
Sidewall damage to the tire is irreparable, and also contains where the tire's strength is . With it damaged it could lead to an eventual blowout. You should replace it.
I wouldn't continue driving on this tire. The damage does not clearly show that the plies would be exposed, but nevertheless, better safe than sorry. The damage is very deep even though the plies are not visible. Sidewall is the structural part of the tire, and thus, damage can easily be fatal.
Even though I partially agree with most answers, I also partially agree with the comment of finleyarcher that it may actually be barely okay. However, to be absolutely sure, the tire needs to be removed from the rim, and it would be ... well, a little strange, to put back the tire in such bad condition. A replacement tire doesn't cost that much. Needing to remove the tire is a good opportunity for replacement.
Also, the area where you have the damage is less well protected from further impacts than the rest of the tire sidewall.
Edit: followed by a comment by Zaid, I realized I need to update my recommendation. Where I live, labor costs are relatively high, meaning patching a tire that can be patched (including removal and reinstallation) costs easily over 30 EUR so presumably removal, inspection from the inside and reinstallation would cost about the same or a little less, whereas a cheap Chinese tire (which the tire in the picture looks like) costs about 50 EUR. In a low-income country, the labor to investigate the tire from the inside would be much lower, whereas the cost of the tire would be about the same. The wonders of globalization: local services cannot be exported.
