Combination thresholds determine when acquisitions or mergers constitute a notifiable combination and trigger merger review. Section 5 defines a combination as acquisitions, mergers or amalgamations that meet statutory thresholds based on assets or turnover (in India or aggregated with foreign assets), group-level thresholds post-transaction, or the value of the transaction; it treats acquisitions of control between competing enterprises and attributes relevant assets, turnover or transaction value to partial business transfers, and supplies definitions for control, group, turnover and asset valuation for threshold application.