Corrections are easier in the notebook section.  Students should arrive at the correct time on examination days.  Students will bring water pot, but not with a regular tiffin box. No clue what a water pot or tiffin box are in any detail.  Students will sit according to the seating-plan of the school.  Guardians are strongly requested not to freak out the students about examination rather they should encourage the students that exam day is much more entertaining and less laborious day for their children. strongly requested - does not really work "freak out" is a very strange thing to say. The children of the students? Always say what to do, not what not to do.  Guardians are strongly encouraged to encourage the students that exam day is an entertaining day rather than causing them any anxiety.  Teachers are helpful in the examination hall as our aim is to make our students to cope up with this competitive, challenging and technology-based world. A constructive and education-friendly exam-environment will be imposed gradually as they move to more advanced classes. What are upper classes?  The examinations are not for grading their academic quality but to identify where they might lack understanding and any shortcomings in their learning which will be polished with the help of our honorable teachers. The fact that you use "honorable teachers" means that your culture is quite different. So my answers may not suit your culture at all.

Good afternoon, I hope these corrections will help you.  Students should arrive at the correct time on the examination day  Students will bring a water pot, but not a regular tiffin box. (I am assuming this is a water bottle and packed lunch)  Students will sit according to the seating-plan of the school.  Guardians are strongly requested not to cause the students anxiety regarding the examination. Please encourage the students that exam day is much more entertaining and a less laborious day for their loving children. (I would write: Guardians are strongly recommended to encourage their students before the exam and to inform them that the exam is more entertaining and less difficult.)  Teachers are helpful in the examination hall as our aim is to assist our students to cope with the competitive, challenging and technology-based world. A constructive and education-friendly exam-environment will be imposed gradually as they are promoted to upper classes.  Examinations are not for grading their academic quality, but to identify where they lack understanding and address any short comings in their education to be refined with the help of our honorable teachers. I hope that this helps you. I wish your students luck on all examinations.