LuaRocks as a package manager has quite some dependencies on other applications/libraries/tools on the system. Here is a list of locations/whats necessary;
most installations will feature two rocks trees;deployment directories contained within the rock trees should probably be added to the LUA_PATH and LUA_CPATH environment variables, so the Lua interpreter can find the modules installed.
When rocks contain commandline scripts, similar to LuaRocks own luarocks and luarocks-admin commands, then they need to be installed in a location where they can be executed. You probably want to add this location to your system path.
Because more rocks are available as source code than as binary rocks, it is probably best to have a C compiler available. MinGW and Microsoft compilers are supported a.o. The compiler should be in the system path, or explicitly configured in the LuaRocks config files.