It sounds like you're asking about rooting an i959 device. The "i959" model number is a bit ambiguous, so let me cover the most likely possibilities:

Most likely: Samsung Galaxy S4 (SCH-i959)

The SCH-i959 is the China Telecom variant of the Galaxy S4. Rooting it is possible but has caveats:

• Carrier: China Telecom (CDMA variant)
• Android version: Typically 4.2–5.0
• Root methods (historically):
  • CF-Auto-Root (Chainfire) — search for CF-Auto-Root-jfltect-schi959
  • KingoRoot / TowelRoot for older firmware
  • Odin flash of a pre-rooted firmware
• Bootloader: Samsung locked bootloaders on some variants — check your specific firmware first
• Risks: Trips KNOX (0x1), voids warranty, potential brick if wrong firmware flashed

Other possibilities

• Lenovo i959 — a lesser-known Android phone; root methods vary
• Could be a typo for i9505 / i9500 (Galaxy S4 international)

What I'd need to help further

1. Full model (e.g., SCH-i959, or the brand)
2. Android version currently installed
3. Build number (Settings → About phone)
4. What you're trying to achieve (custom ROM, debloat, etc.)

⚠️ Warning: Rooting voids warranty, can trip security flags (KNOX/e-fuse), and risks bricking. Back up first.

Which device/brand is your i959? I can give more specific steps once I know.