No. Never cross-flash firmware. Even within the TechnoSat family, the T-786 uses a different mainboard. You will brick your device.
For ongoing support, join dedicated TechnoSat user groups on Telegram or Facebook. The satellite community is active, and version 17 upd is currently the most discussed firmware in 2024–2025 cycles. technosat t 786 hd software 17 upd