yar abt gear oil since that ur car aint auto u can change it at 1 lack km since gear oil of manual cars itna ganda nae hota compared to auto tranny gear oil! bcoz auto tranny gear oil has 2 functions aik toh it keeps the parts lubricated secondly it even acts as a coolant to keep ur transmission cool n doesnt let it over heat hence auto cars ka gear oil should be changed after every 40,000km! since ur car has alread done 90k drive it 10k more and then change the gear oil,the brake oil,coolant,timing belt at 1 lack km! and check the other belts for cracks or for an other signs of wear and tear!
