Database Parameter change when will it take effect

Hi,

Using brtools when we change a particular Database Parameter a screen appears as below

Pos. Parameter Modif. Spfile Inst. Deft.

1 - active_instance_count spfile no * yes

2 - aq_tm_processes both no * yes

3 - archive_lag_target both no * yes

4 - audit_file_dest spfile no * yes

What i wanted to know is if I change any parameter from this, when will it come into effect. Do these changes happen online or do they need a database stop and start

Thanks in advance,

Regards

Alfred