First of all congrats on ur new purchase.
I own a 5 grade AXIO X manual gear with genuine verified mileage of 40000 km since last six months (now 43000 km). As far as my experience is concerned, there is no need to change any fluid except engine oil in a car like mine. Many of my friends also suggested this. Since, your car has a 90k km mileage, so you should go for change of transmission oil, brake pads/service, brake fluid, spark plugs, tb cleaning etc. But stick to OEM parts only. Instead of 5W-30, 10W-40 is not a wise decision. Once, u use 5W-30, and if there is some oil decrease etc. after its change, then u can go for 10W-40. But this is my opinion and still its ur choice.