There is alot of fake oil in market make sure you are using original oil. Secondly if your car idles alot it that can be the reason too.
As i have heard Altis takes around 4.25 liters engine oil make sure you are putting correct amount in the first place.
He said just change it to ZIC HIFLO.
Bcz synthetic oil has washed its carbon so Hiflo will amke carbon and ur problem would be solved.
and this is not at all solution of your problem the above statement makes No sense to me.