Which part should we start first?

You can do the sections in whichever order you want - there is no best order. Just make sure that you allocate you time and that you hand in an answer for every MCQ in Sections A and B (even if they are guesses because you could not get the answer or ran out of time), and that you write something for every part of every question in Section C (even if again you get stuck or you run out of time). You are aiming to get more than 50%, and if you do what I have written then you should get more than 50% :-)

Sir there is a lot of rough mcq work that we have to do in this exam. Just want advice from you. How do we answer questions if for example i attempt a section c question first thn my second question is from section b which is obviusly with lot of mcq rough work? Just writing it above a page will be eoniguh to refrence? and it wont make the marker confused? And what do u suggest which section we should attempt first? i personaly think its better to attempt section C first as we do get step marks over there and thn attempt section b and a of course depending upon the diffciulty of questions.

There is no problem with rough work - just make very sure that you write clearly at the top of the page that it is workings. (This only applied to Sections A and B - for Section C it is the workings that get the marks and so you need to show them clearly). There is no 'best' section to start with - it is whatever you feel most happy with. Whichever one you start with then make sure that you allocate your time and so have time to attempt all the sections :-)