I need to query particular column in DB w/c is described as `VARCHAR` that I need to convert into Time Format (`HH:MM`) and then decode to its range value, to explain further... The column stores data when (time) a particular deal was made w/in the day and instead of returning the exact time it should return the time range it was done.

```
Col_1 is VARCHAR2(6)

select col_2, col_1 from table

Col_2 ||  Col_1

A     ||   9:56

B     ||  10:03

C     ||  21:53

```

My desired Output would be

```
Col_2  || Col_1

A      || (09:00 - 10:00)

B      || (10:00 - 11:00)

C      || (2100 - 2200) 

```

Really appreciate all your comments, as I'm stuck playing with this part for a couple of days now and its giving me nightmares, sorry I'm new to DB Oracle SQL stuff and still learning. :)