Yes, Xiaomi Poco M3 Pro 5G has 5G, and that is only usable and fully beneficial when there is a 5G network available around.
The Xiaomi Poco M3 Pro 5G has 5G network support. But that can only be used when there is a 5G network available in the region where you are using the phone. the supported 5G network band of the phone is 5G:n1,n3,n7,n8,n20,n28,n38,n40,n41,n66,n77,n78. The Xiaomi Poco M3 Pro 5G is a better option if you are looking for an entry-level, mid-range phone.