Models for game

Hello, i was wondering how would i use models from places like turbo squid? i have for example a HOUSE download in that 7 diffrent winrar files, in each one of those, 3 truevision TGA images and a C4D file

you should extract the archive. by extracting the first archive the others will be extracted too and the files will be merged. the c4d is the file format for cinema 4d and you should use the tool to convert the file to fbx or another unity supported format and install the c4d on your system to let unity automatically do the conversion.