See the conventional method which 99% of the aspirants will recommend that do Biology first, then Chemistry and then Physics. I have done this, didn’t suit me though but I will tell you what’s the logic behind this and what I did.
The logic is first you complete Biology as it will generally be the easiest and can be completed in 40 minutes which leaves you 2 hours and 20 minutes for Physics and Chemistry and the easy biology will give you a confidence booster. Chemistry is generally average which can be completed in 50 minutes or hour which leaves you with 1 hour and 20 minutes approx for Physics which is considered enough and you will have enough time for revision.
The major con with this thing is that, which I have felt personally, is after doing Biology and Chemistry, I used to get exhausted and if Physics questions are tough which is the case many times, it would leave me tense and I couldn’t give my full efforts at Physics. You will then get more tense after seeing that the clock is ticking away and you might not get enough time for revision or unattempted questions.