Instead of looking for part14.rar in isolation, search for the complete set. The firmware is likely labeled as Micromax 50 Canvas 3 Stock Firmware (Flash File) .
Look for the file on reputable firmware repositories. AndroidMTK Micromax Stock ROM RepairMyMobile Download MICROMAX L40CANVAS Firmware USB part14 rar
Is the device a or a smart TV (L40Canvas) ? Instead of looking for part14
Finding specific parts of multi-part archives (like "part14.rar") for older firmware can be challenging as original hosting links often expire. Download MICROMAX L40CANVAS Firmware USB part14 rar