caltex coolant sold in Pakistan is perfect for use, just make sure to completely clean the system first with citric acid - you dont need to buy fancy liqui moly flush or branded flush.
Just usual tartaric acid from karyana store works (mercedes benz service manual procedure)
once clean, fill up system with coolant and water mix. There is a 50% chance that the water pump intake pipe is corroded too, replace that.
If you see headgasket leak after this job then its probably a corroded block which happens from not using coolant.
basf glysantin G-05 and G48 are great too - they are HOAT coolants and easily available in Pakistan.
