TISSNET syllabus consists of questions related to General Awareness, Logical Reasoning, Maths and English Proficiency.  Here are some topics covered in the syllabus:

General Awareness: Geography, History,, Personalities, Current Affairs, etc.

English Language Ability: Vocabulary, Analogy, Reading Comprehension, etc.

Maths & Logical Reasoning: Basic Geometry, Percentage, Time & Distance, BODMAS, Ratio, etc.

To prepare the exam Focus on current affairs, economics, politics, amongst other things. Manorama Yearbook is an excellent book for preparing for Tissnet GA section, For quant, Logical reasoning and Data interpretation you can refer R s agarwal, Arun sharma, RD Sharma

Good Luck!