Does excess quantity of Gear Oil do any harm??

Today I got the Gear Oil of our Indigo LS (1,58,924 kms) replaced with new one. But I doubt the mechanic poured 4 litre oil instead of 3.3 litre (Recommended by TATA Motors Ltd). Will the excess 0.7 litre Gear Oil do any harm to the Gearbox in short or long run?
If yes, then I will have to remove the excess oil from the "level check" hole.

I know that if Engine Oil is excessively poured instead of Recommended Quantity, then that excess EO (Engine Oil) flows into exhaust chamber. But what about Gear Oil.
Please guide me.

Not advisable. Excess of anything is bad. Like excess engine oil harms the engine gaskets causes more smoky exhaust.

So can you please tell me the adverse effects of excess Gear Oil (in excess of 30-40%) on the Gearbox, or any other part of car?

It will damage the gearbox gasket and oil seals