A PAC file is a firmware archive specific to devices running on Spreadtrum (UNISOC) processors. It contains all the necessary partitions for the phone to function, including:
Based on the device model (which is likely a variant of the Nokia C1 Plus, C1 2nd Edition, or C2), the "feature" you are looking for is how to handle a .PAC firmware file . nokia ta1165 firmware pac file install