i also have this power supply from intex (Intex IT-25F2) 600w 20-4 pins
If this is your IT-25F2, it's from a bygone era when power supplies had a mains outlet for a monitor and only 20 + 4 pins for the motherboard. It's probably somewhere between 10 and 20 years old and should quietly be "put out to pasture" and never used again. Don't risk your motherboard with such an ancient design. It'll probably be 'common rail' (I think that's the correct term) with insufficient power on the 12V rail for a big GPU. Not worth the risk.
I'm curious if it says 600w there
This link shows three power ratings 450W, 500W and 550W. I'm not sure if there are three versions or something else? Perhaps they just stick three different labels on the same PSU and sell them in different parts of the world. 600W in cold climates, 500W in temperate and 450W in desert locations.
https://www.exporters.sg/showroom_item/2125418/Power-Supply-Accopia-500W-INTEX-(IT-25F2.html
Maximum Output : 450W / 500W / 600W. Dual ball-bearing Fan 80mm for excellent
thermal control in front & back. Enhanced +12V output capability. 20+4 pin cable
shielding. Fan Type: 2 FAN (Size : 80 X 25 ). Cable length: 40 CM. Connectors :1 x
20+4 pin connector,1 X 4 pin connector SATA 1 Nos (400 / 450W) 2 . Nos (500 /
600W) , HDD 3 Nos (400 / 450 /500W) 5 Nos (600W)FDD. AC Input: 230V 50-60Hz
5A.
DC Output +3.3V : 30A +5V:29A +12V:18A -12V:0.5A +5VSB:2A Power Cord Option.
On/Off Switch: Power On/Off switch. +12V Rails: Enhanced rails +12V X 1. Dimension
:51X42.5X18 Cm.