Based on the provided legal document, the key legal principles and conclusions are as follows:

1. Filing of Charge-Sheet Within Time: Once a charge-sheet is filed within the stipulated period under Section 167(2)(a)(ii) of the Cr.P.C., the question of granting default bail or statutory bail does not arise. The filing of the charge-sheet is considered sufficient compliance with the investigation period requirements, regardless of whether cognizance has been taken or whether sanction to prosecute has been obtained (!) (!) (!) .

2. Authority to Extend Detention: The authority of a Magistrate to extend detention beyond the prescribed period (90 days for serious offences or 60 days for other offences) is limited. If the investigation is completed within the stipulated period and the charge-sheet is filed, the Magistrate no longer has the authority to extend detention and must release the accused on bail if they are willing to furnish it (!) (!) (!) .

3. Effect of Non-Obtaining Sanction: The failure to obtain sanction to prosecute does not affect the validity of the charge-sheet filed within the statutory period or the legality of remand orders passed during this period. Sanction is a separate procedural requirement for prosecution and does not impact the completion of investigation or the filing of the charge-sheet (!) (!) .

4. Remand and Investigation Stages: The power of remand during investigation is governed by specific provisions, and once the investigation period has expired, further detention without a valid charge-sheet or cognizance is illegal. After filing the charge-sheet, the proceedings shift to the trial stage, where the court's powers to remand are governed by different provisions, namely Section 309 Cr.P.C. (!) (!) (!) .

5. Rights of the Accused: If the charge-sheet is filed within the prescribed period, the accused's right to statutory or default bail is extinguished. The accused's entitlement to bail thereafter depends on the merits of the case, not on the procedural timing of investigation completion (!) (!) (!) .

6. Conclusion: The filing of the charge-sheet within the statutory period is a key factor that concludes the investigation phase and renders any further detention beyond the period illegal. The absence of sanction to prosecute does not invalidate the charge-sheet or the detention orders passed during the investigation period. Therefore, the petitioner is not entitled to release on bail solely on the ground of non-obtaining of sanction, provided the charge-sheet was filed timely (!) (!) .

In summary, once a charge-sheet is filed within the statutory period, the legal basis for default or statutory bail ceases, and the accused's detention beyond this period without proper proceedings is unlawful.