This is not fixed if it's not the same number of characters for each row.
So if there is no delimiter, there is no way to easily create a datastore. In addition you have null values.
Even regex is not possible because emp_name and dept_name are both composed of letters. Unless the emp_name is always on 3 characters as in your example. If it's not the case, I don't think it's possible.
You could try this:
1. Define the file source as fixed
2. Select Other under the Record Separator, but do not enter any code
3. Define column names and length as needed.
4. Check how the data look using View Data
It worked for me.