You can try:

• Sainik School Class 6th Guide 2020 by Arihant
• 25 practise sets for Class 6th by Upkar
• Sainik School Class 6th Guide 2020 Hindi by Arihant

You need to have a proper planning for studying for Sainik school admissions. The exam has 2 papers, Paper 1 and Paper 2. Paper 1 has Mathematics and Language Ability test. Paper 2 has Intelligence test which contains 100 marks. Please check the entire syllabus at our page: https://school.careers360.com/articles/sainik-school-syllabus