Brother Dr. Baloch Sahib is talking about the engine oil in his post, and not the coolant.
As per https://www.toyota-indus.com/after-sales/parts/chemicals/ , following details are available regarding 02 types of coolants currently offered by Toyota Indus in Pakistan:
Toyota Genuine Long Life Coolant (Pre Mixed, Anti Rust & Anti Freeze & 100% concentrated)
Toyota Genuine Super Long Life Coolant (50/50 Pre-Mixed, Anti Rust & Anti Freeze)
In LLC, you need to add an equal volume of pure water, and make the mixture before hand, in a bucket, tub, etc. SLLC comes 50/50 premixed from the company, you need not add any pure water.
In both cases, first you need to completely flush your radiator (there are tutorials and videos available on the internet, you can check how to do this job). Then add the coolant in reqd. quantity in the radiator. During this, ensure that there is no air / bubbles in the systems and they all need to be bled, otherwise, you may face engine heat-up issues.
I think, it will not be OK!