Rs 800? - what?
the fan clutch oil used to be abt Rs 100/- for abt 50ml in a toyota bottle, 3 viscosities to choose from.
5000 cst oil was used in old 5K engines etc, those are obsolete even in Pakistan now.
Buy that 12500 cst oil - it will be your best option. Infact pack it in 100ml bottles and sell to others too.