An order for release on bail under proviso (a) to Section 167(2) may appropriately be termed as an order-on-default.

Cr.P.C. S.167(2) Proper Order:  Indeed, it is a release on bail on the default of the prosecution in filing charge-sheet within the prescribed period. The right to bail under Section 167(2) proviso (a) thereto is absolute. It is a legislative command and not court’s discretion. If the investigating agency fails to file charge-sheet before the expiry of 90/60 days, as the case may be the accused in custody should be released on bail. But at that stage, merits of the case are not to be examined. Not at all. In fact, the Magistrate has no power to remand a person beyond the stipulated period of 90/60 days. He must pass an order of bail and communicate the same to the accused to furnish the requisite bail bonds.”-Rajnikant Jivanlal v. Intelligence Officer, Narcotic Control Bureau, (1989) 3 SCC 532