Whether a Muslim can be called as Fasiq? Yes…
Fasiq is a person who does sin (major or minor) and

1) do not attempt to improve ​himself and

2) do not take steps to stop himself from doing that sin and

3) do not feel guilty of sins (major or minor) and

4) do not ask for forgiveness and

5) do not repent

Example, if a Muslim drinks liquor and says or believes that there is nothing wrong in drinking or call himself a social drinker is a kafir…

But if a Muslim who agrees and believe drinking is haram but still drinks and 1) do not attempt to improve ​himself and 2) do not take steps to stop himself from doing that sin and 3) do not feel guilty of sins (major or minor) and 4) do not ask for forgiveness and 5) do not repent will fall in category of Fasiq

Fasiq will be in hell if his bad deeds are more than his good deeds

Another example, if a Muslim who smoke, watch movies or TV series or listen to songs etc and 1) do not attempt to improve ​himself and 2) do not take steps to stop himself from doing that sin and 3) do not feel guilty of sins and 4) do not ask for forgiveness and 5) do not repent will fall in category of Fasiq

1) A Muslim must not be called a kafir, mushrik, munafiq or Fasiq unless there is clear evidence of shirk n kufr for it like idol worshiping, asking for help other than Allah,rejecting any pillars of Iman, rejecting any verse of  Quran or hadees, justifying sin , doing haram things n boasting n not asking for forgiveness n do not repent etc..