Both are relatives (OPPO and realme) and cost the same. But one has no 5G and the other has no protection rating.

Short answer

OPPO A6 Pro - 7000 mAh, 80 W. realme 16 5G - 5G, lighter (183 g), a 50 MP front camera.

Key differences

SpecOPPO A6 Prorealme 16 5G
ChipMediaTek Helio G100MediaTek Dimensity 6400 Turbo
Display6.57", AMOLED, 1080×2372, 120 Hz6.57", OLED, 1080×2372, 120 Hz
RAM / storage8/256 GB8/256 GB
Rear cameras50 MP + 2 MP50 MP + 2 MP
Front16 MP50 MP
Battery7000 mAh6550 mAh
Charging80 W45 W
ProtectionIP66 / IP68 / IP69IP66/IP68/IP69/IP69K
Thickness / weight8 mm / 188 g8.1 mm / 183 g
Pricecurrent pricescurrent prices

Specs come from the device pages on Smartphone.ua.

5G

The Helio G100 doesn't support 5G, the Dimensity 6400 does. MediaTek Helio G100 and MediaTek Dimensity 6400 Turbo.

Battery and protection

OPPO - 7000 mAh, 80 W and IP66/68/69; realme - 6550 mAh, 45 W and even IP69K.

Verdict: who should buy which

  • Battery life and protection - OPPO A6 Pro.
  • 5G and selfies - realme 16 5G.

FAQ

Does the OPPO A6 Pro have 5G?
No.

What battery does the realme 16 5G have?
6550 mAh.

How much do they cost?
The same.

Read also