This is my personal opinion
Tqwl ( Tatkal waiting ticket) sleeper class
If your traveling distance is just under 500 km from the origin station then TQWL upto 10 no. Can be...
more... easily confirmed .....
But if your destination station is more than 500 km then it's very very rare chances that TQWL pnr gets confirmed
In case of Ac class
TQWL pnr above than TQWL 1/2 can be confirmed depending on the train or route ...
More than TQWL 3 there are only 10 percent chances that pnr will get confirm