Here are some of the preparation tips to prepare for DULLB entrance exam.

DU LLB exam has a strong focus on Legal Aptitude and Indian Polity, especially as it relates to the legal aspects.It is an entrance exam for admission in one of India's most premier 3-year LLB schools.
Plan a strategy: It is a must to schedule a study-plan. An intensive preparation strategy is needed which includes as many as 6 hours of regular studies to crack DU LLB entrance exam. you must study at least two subjects every day and must practice at least one vocabulary / English and one reasoning exercise daily.
There is no defined syllabus for GK and current affairs in this exam. You can focus on important awards each year  sports, science, literature and arts, Physical geography, science and environment, Important happenings in the area of the Indian Constitution or Justice system
Mocks form an important part of the exam preparation. Look for a good online mock test series, and aim to write at least 6-8 mock tests before the actual exam. Reproduce the exam conditions as much as possible.

Good Luck!