The controlling Act is the Fair Work Act 2009 (Cth).

(a) Under s 117, the minimum period of notice of termination owed is 4 weeks.  
Working: 6 years of continuous service falls in the "5 years or more" bracket (4 weeks). The employee is under 45 years of age, so no additional week applies.

(b) Under s 119, the amount of redundancy pay owed is 11 weeks of base pay.  
Working: 6 years of continuous service falls in the "at least 6 but less than 7 years" bracket (11 weeks).