The combined graduate level service exams are due to start from end of July this year ( the first of the four exams). So, your brother has only 4-5 weeks time left out. So, your brother does not have time for a detailed analysis. He should quickly refresh the below and focus on practicing to be accurate, fast and adjust the times regularly so that he is confident of the time issue. The pattern of the actual answer paper should not come as a surprise.
A. First is to know about the pattern of the exams.
He would have ONE hour to answer 100 questions of 2 marks each. It would be an online exam. Of the 100 questions equal number are from General knowledge and reasoning, general awareness, aptitude ( quantitative) and English comprehension.
B. Now that you understand the pattern, next for our brother is to quickly mark the areas of his strengths and weakness in the above FOUR areas
1. General intelligence and reasoning:
Here the trick is to understand the question first and then answer because, here the students capability to think logically and formulate a solution plan is checked. Here we have numeric series, Venn diagrams, word sequences, odd man out etc.
2.General awareness: In this section although easy, you have a wide range of subjects from which questions can be asked. Most questions come from basic sciences ( physics, chemistry, biology), history, basic law questions related to parliament, constitution, political parties etc. Also some questions come from national statistics related to economy and population.
3. Aptitude (quantitative): This section is like mathematics paper, if you have a sound grasp, you can score well, guess work does not help here. The common areas are related to interest ( simple, compound),algebra, graphs, questions related to time and distance etc.
4. English comprehension: This is one area of the whole 1st step exam where a candidate can score well when compared to other three areas. Here you will be tested on comprehension and reading skills, phrases and sentence pattern,correctness of use of verbs and grammar.
C. Now he can allocate one week each for the four major areas so that he gets the full benefit of the short duration of time at hand. There are many sites that have free mock tests, some need your brother to register or login with a valid email ID.
D. Apart from knowledge, some basic tips are needed for such competitive exams. For instance, there is no sectional time limit ( so he can quickly finish the sections that he is very confident first, and then move on to the ones that he need more time). There is negative marking. So, general awareness and English should be finished quickly in around 15 mintues and save precious 5-10 mintues for the other two sections.
Develop a method to read and quickly understand the question so that you can save time. Quantitative aptitude is the one that is most taxing and you need to have clear cut ideas about formulas, steps and concepts of profit, loss, interest etc.
This site (https://www.examrace.com/SSC-CGL/SSC-Practice-Questions/) has free downloads for questions related to all the four sections including solved test papers.
Now is the time not to read detailed textbooks, manuals or reference books. He now needs to get the hang of the difficult areas, quick revision of subject matter, practicing mock papers and timing it. He has to get into the habit of checking the sections and completing the easy ones in 10-12 minutes and the difficult ones in 15-18 minutes. It is important NOT to linger on a single question for more than 45 seconds and in a section for more than 15 minutes each. Last but not the least, he has to remember a correct answer is = 2 marks and wrong answer is MINUS 0.5. So, no guess work.