how can I convert **int "Hour"** and **Int "Minute"** into time and then get percentages of two different time?

to get total of time from **int** column I am using 

```
Format((SUM([THOURS]) * 3600 + SUM([TMINUTES]) * 60 + SUM([TSECONDS])) / 3600,'00')+':'+Format((SUM([THOURS]) * 3600 + SUM([TMINUTES]) * 60 + SUM([TSECONDS])) % 3600/60,'00') as "Total Time"

```

I got the perfect time from the above query.

But now i wan to get percentage calculation from my two **int "Hour"** and **Int "Minute"** column table. 
[![enter image description here](https://i.stack.imgur.com/NliSS.jpg)](https://i.stack.imgur.com/NliSS.jpg)

I have tried 

```
DECLARE @MS INT = 235216
select cast(dateadd(ms, @MS, '00:00:00') AS TIME(3))

```

it's not working as my requirement. 

Is anyone have an idea for same?