Are you making your own gas tube? Are you making your own gas block? If not, then no, you cannot put your gas port just anywhere.
It seems as though you’re not familiar with AR-15 designs. As I asked in my first above - What guidance did you use to cut the gas block journal and shoulder in your profile?
You SHOULD have chosen a gas length, which would dictate port location and size, as well as your gas block journal and shoulder position. If that shoulder is at an arbitrary length, you’ll have to cut, flare, and sewage your own custom gas tube length. AR’s have standard gas lengths for a reason. Your gas port should be placed accordingly, then your gas block shoulder cut based on the port position. The port should be placed according to your desired gas system length, then the shoulder placed 0.295” +/-0.005” behind the center of the port. The port size is dictated by the cartridge and gas system length.
The entire enterprise is kinda misguided. What you SHOULD have done is pull the extension, set the barrel back, and rechamber to cut out the old, obviously burned out throat and leade. Sure, it’s gonna go bang (if you can resolve your gas length issues), and if you have no performance expectations, it’ll be fun, but you kept the worn out part of the barrel.
Since it looks like the old barrel was a straight profile, I would have kept the old gas journal and shoulder, and cut the barrel out of the middle, such I would totally eliminate the old chamber, throat, and leade.
But here we are, what’s turned is turned - what’s your length from the gas block shoulder to the end of the extension?