That kind of looks like a mess.
As has been said if it's normal phone wire for RJ11 jacks it does not matter much.
If it's network cable then you never splice it. You typically put a RJ45 connector on each end of the wire and use a female to female coupler.
You NEVER untwist any more of the network cable than is absolutely necessary to get the RJ45 connector on.
If you have never done any RJ45 connector crimping then buy a decent crimper, some RJ45 connectors and several feet of network cable and practice. And practice.
Passthrough connectors are much easier but the crimper is more expensive.
Also handy is the outside jacket stripper. It's got a round blade in a hole and your twirl it around a few times.
After your done you need a Fluke network cable analyzer to check the network cable and connections to see if it meets the specs. That's $2000.