Here is what my dealer told me:
TRANSMISSION/REAR-END both take universal tractor tranmission/hydraulic fluid (like John Deere 303 or R&O Hydraulic Fluid). He said thats what Mahindra told him (although he wouldn't recommend R&O).
BUT, he also said that you could use 80w90 gear oil too.
NOW FROM EXPERIENCE:
My tractor shifts A LOT better when using the 80w90 gear oil.......I had that in there before I changed to the universal fluid........When I change it again i'll go back to the gear oil. It works better for my tractor and my dealer said its ok to use it..........As for the hydraulics, i'll just use the JD303.
The transmission/rear-end has a total of (3) square head oil DRAIN plugs (I think they might be called "bull" plugs), where 2 are under the tractor and one is at the very bottom of the rear-end directly centered below the PTO shaft.
The fill plug (the only one) is to the right of the gear shifter.........The check plug (the only one) is on the right side of the transmission towards the center (you'll know it once you see it).......When oil runs out of that hole, it is full (it takes a lot. I believe a little over 5 gallons)....
The Hydraulic system has a dipstick type "bull" plug (the only one) behind the seat on the right side of the tractor. Directly right below it is the drain plug (the only one).
I HAVE THE OPERATOR'S MANUAL, ENGINE SERVICE MANUAL, AND CHASSIS SERVICE MANUAL...........
OH!!! just right off the top of my head, the FUEL TANK holds 9.24 U.S. gallons and the tractor's TOTAL WEIGHT (with all fluids, 3pt. hitch, no attachments, etc.,) is 4092 LBS (without liquid in the tires)......I guess thats why it PULLS SO GREAT!!
I hope I didn't make this too complicated. It took me right at an hour to type this.............Hope this helps and if you need anything let me know.
Travis R