Some synonyms for “centralising” are “concentrating”, “consolidating”, and “unifying”.
“Concentrating” implies bringing things together into a focused area or group. For example, “The company is concentrating its operations in one location.” This shows that efforts are being made to centralize by gathering activities in a specific place.
“Consolidating” also suggests bringing things together for greater efficiency or control. For instance, “The government is consolidating power in the central administration.” This indicates that power is being centralized by combining different elements under a central authority.
“Unifying” emphasizes bringing diverse elements together into a single entity or system. For example, “The new policy is aimed at unifying the different departments.” This shows that the goal is to centralize by creating a unified whole.