Needrom is a well-known repository for Android firmware, particularly for MediaTek-based devices. The official Vivo Y75A ROM listed there includes (Android 7.1.1). However, the site requires user registration (free) to download files and user reviews suggest that some uploads may require authentication patches.
, which is primarily a China-market device, a "global firmware" typically refers to flashing a ROM that includes Google Play Services and international languages. Because this device is powered by a MediaTek MT6763 processor, flashing is usually done via the Smartphone Flash Tool (SP Flash Tool) Pre-Installation Requirements Backup Your Data vivo y75a global firmware
The Y75A originally shipped with based on Android 7.1 (Nougat) . Needrom is a well-known repository for Android firmware,