this is a bit confusing.

 

For example: 

 

when i check the GP5 file in guitar Pro, or TuxGuitar, i see BPM is 90.

When i search the song on songbpm.com a BPM of 169 is given....

what's the correct one?

Probably better to go with the one in guitar pro, the actual bpm could be 170 but it could be tabbed out at 90 with double note speed (using quarter instead of half notes at nearly double bpm). I normally use the guitar pro as a baseline and move the beat markers around as needed in eof to make it match better.

 

If you want to double check try tap for bpm and if its the same as songbpm.com then its the song is tabbed out with half bpm but double note speed.

As long as its close enough it shouldn't matter too much. Or try setting it to 85 (half of the songbpm.com one) and see if it sounds any better