Step 1: Read the question.
Under Section 167 of the CrPC, 1973, default bail (statutory bail) is a right if the investigation is not finished within a set time. We must find that time.
Step 2: Understand the aim.
Section 167(2) protects personal liberty. It stops the police from keeping a person in detention forever while they investigate.
Step 3: Learn the time limits.
If the offence is punishable with death, life imprisonment, or imprisonment of not less than ten years, the limit is 90 days. For all other offences, the limit is 60 days.
Step 4: Understand the right.
When the period ends and no charge-sheet is filed, the accused gets a right to default bail if he is ready to give bail.
Step 5: Check the other options.
The 120 days idea, the end of police custody, and a fixed 30 days for all offences do not state the general rule of Section 167.
Step 6: Final answer.
So default bail arises after 60 days or 90 days, depending on the punishment.
\[ \boxed{\text{After 60 days or 90 days, contingent upon the maximum punishment prescribed for the offence.}} \]