TP-Link Archer AX18 vs AX12: What is the difference?

The TP-Link Archer AX18 and Archer AX12 are the same router sold under different model numbers for different regions. Both are AX1500 Wi-Fi 6 routers with identical wireless speeds (1,201 Mbps on 5 GHz, 300 Mbps on 2.4 GHz), the same port layout (1 gigabit WAN + 3 gigabit LAN), four external antennas, OFDMA, MU-MIMO, WPA3, and beamforming, per TP-Link's product pages for both models. If you are shopping in India, the AX12 is the variant sold here.

TP-Link uses different model numbers across regions for the same hardware. The AX18 is listed on TP-Link's UK and European product pages. The AX12 is listed on TP-Link's India product page. The core hardware, including the 1 GHz dual-core processor, is shared. The only potential differences are firmware features that may be enabled or disabled per region. The AX18's product page lists a built-in VPN server (OpenVPN) and EasyMesh support. The AX12 received EasyMesh support through a firmware update recently. 

If you see both model numbers available online in India, the AX12 is the officially distributed variant with local warranty through TP-Link India. Importing an AX18 may get you the same hardware, but warranty claims become complicated since TP-Link India services the AX12 SKU, not the AX18. The price difference, if any, is not worth the warranty risk.

Verdict: these are the same router. If you are buying in India, buy the Archer AX12. It is the locally supported variant with the same specs, the same performance, and a warranty that TP-Link India will honour.