I can’t stop a tail pipe leak after installing in bathroom sink
From the photo it looks like the tailpipe is misaligned with the hole in the sink (collar offset to the right so that it overhangs the sealing surface of the sink on the right and barely covers it on the left). This is quite a common issue and if the offset is bad enough, the gasket won't even have anything to seal against on the left side and instead the collar will just force that part of the gasket into the hole.
This issue can also be made much worse if the gasket is a bit too small for the collar and the hole. I'm used to the outer diameter of the gasket being at least about the same as the outer diameter of the collar.
Try realigning it to see if you can improve the situation. If the only way to get the collar and the hole aligned is to tilt the tailpipe, it's likely you'll get another leak due to the two sealing surfaces not being parallel (so that when the collar is tightened just enough for one side, the other side still has a big gaping hole). If that happens, just use a thick-ish gasket of the &quot;spongy rubber&quot; variety, which tends to compensate for these issues much better than solid rubber gaskets.
A good way to look for leaks is to tighten the collar just lightly (so that it doesn't fall off and the gasket is held in place), get a strong light source (a powerful flashlight or something) and shine it down the sink. If you see any light shining through anywhere near the gasket, that's where a leak will likely occur once you tighten properly.