Changing geopolitics: UNSC still reflects the geopolitical architecture of the WW II despite the change in power relations in world. The developing nations, including India, now play a larger role in both the international economy and politics, yet are not represented in the forum.
Reforms Long Overdue: It was expanded only once in 1963 to add 4 non-permanent members. Although the overall membership of the UN has increased from 113 to 193 but no change in the composition of the UNSC happened.
Inequitable economic and geographical representation: Major economic and regional powers like Germany (Europe), Japan, & India (Asia) and Brazil (Latin America) are not yet a part of UNSC. Similarly, there is no permanent member from Africa, despite the fact that 75% of its work focused on Africa it has no permanent member from this region.
Crisis of legitimacy and credibility: various issues including its Interventions in Libya and Syria in the guise of responsibility have put the credibility of the institution in jeopardy.
North South Divide: The permanent UNSC membership of P5 today only portrays the big North-South divide in the decision making of security measures.
Emerging issues: Issues such as transnational threats, deepening economic interdependence, worsening environmental degradation also call for effective multilateral negotiations for reforms yet all critical decisions are still being taken by the veto-wielding permanent members of the Security Council.