We certainly can’t tell from a few pictures. Best way to know is to follow the purchase trail. Did you buy it directly from Titleist or an authorized dealer? If not, can the person you bought it from show the original invoice? Those would be the only guarantee. If you are still unsure, take it to a local authorized Titleist golf shop that has the ability to do a side by side comparison.

I am not sure but on the weighting system the ring is wight but if you look on the website it isn't whit it is black.

Where did you buy it from.

If I had a nickel for every time somebody asks that question...
Fakes are so good these days that I would be surprised if even Titleist could help you with that question based on a few pictures. Being as you are questioning it's authenticity, I would venture to say you did not get it from a reputable dealer, and now every mishit will leave you wondering whether it's fake or not.

And I’ll bid you down to 2 cents for every.. and still get a new set of clubs every year.
3 rules to check before buying -
1. There are price limits for new equipment. If the price is too good, it isn’t.
2. The internet offers no guarantees, with the exception of brick and mortar stores with a website
3. If you can’t verify the ownership/chain of custody, buy at your own risk. Accept the risk up front. Or walk to a local dealer.

These are the key points. If the price is significantly lower than the retail price (all authorized sellers have price maintenance agreements) then it was either stolen or it is a fake.

For me it is looking very nice. I would guess that it is a genuine club.
If you know the provenance and it is fitting to you, depending on price you may did a good deal but..

My only question is why you did not bought it from an authorized Titleist’s dealer.
Yes, you will pay more but you will obtain a club with the right shaft, right loft, right specs and an oem product.

I might be totally off on this, but the color of the ring on the weight may differ if a different weight is used. The different colors may well be used to identify the weight of the weights, if you understand what I am saying.

Yes that would probably be right.

I would be surprised if the GT4 would be counterfeited. Thats a lot of work for probably the least selling model in the lineup.

Does that head have a Tensei IK Black shaft in it? It appears to have been originally sold in the UK and the number is legit.
Word to the wise, do not purchase items off eBay.