Hi Ajith,
Fluid topups are not normally done during an MOT. Please refer to the
mot checklist guide to see what is being examined by the mechanic during the MOT. You should be topping your engine oil & coolant, brake fluid regularly to maintain your car in good condition. Some garages will do it for you for an extra fee but like I said it is not included in the price for a basic MOT test.
Also, if there's anything wrong with your vehicle during the MOT test, you will need to pay for the repair costs to pass the test. It means that you will have to take your vehicle down to the garage again as it is most unlikely that they will do the repairs on the same day for you and you will have to pay another fee for the 2nd MOT. They will normally discount the second MOT for you though.