You cannot pursue 3 year law program directly after class 12, it is for the graduates. However, here is the road map to your law journey.

1. Opt for an Integrated Law Course: After Class 12, you don't directly enroll in a 3-year LLB program (that's for graduates). Instead, you pursue a 5-year Integrated Law Course. Common options include:
   • B.A. LLB (Bachelor of Arts & Bachelor of Laws) - Most common
   • BBA LLB (Bachelor of Business Administration & Bachelor of Laws)
   • B.Com LLB (Bachelor of Commerce & Bachelor of Laws)
   • B.Sc. LLB (Bachelor of Science & Bachelor of ¹ Laws)
   • B.Tech LLB (less common)
2. Eligibility:
   • You must have successfully completed your Class 12 (10+2) examination from a recognized board.
   • Most universities require a minimum percentage, typically ranging from 45% to 50% in Class 12 (can vary for reserved categories).
   • Students from any stream (Science, Commerce, Arts/Humanities) are generally eligible.
3. Entrance Exams (Crucial Step): Admission to most reputable law colleges (especially National Law Universities - NLUs) and good private universities is based on national or university-level entrance exams. Key exams include:
   • CLAT (Common Law Admission Test): The most popular exam, required for admission to 24 National Law Universities (NLUs, excluding NLU Delhi) and many other private law schools.
   • AILET (All India Law Entrance Test): Specifically for admission to National Law University (NLU), Delhi.
   • SLAT (Symbiosis Law Admission Test): For admission to Symbiosis Law Schools.
   • LSAT--India (Law School Admission Test - India): Accepted by numerous private law colleges in India.
   • MH CET Law (Maharashtra Common Entrance Test for Law): For law colleges in Maharashtra.
   • CUET (Common University Entrance Test): Some central and state universities might use CUET scores for their integrated law programs.
   • Other university-specific exams (though many are consolidating under CLAT or CUET).
4. Exam Preparation: These entrance exams typically test aptitude in areas like:
   • English Language (including Reading Comprehension)
   • Legal Reasoning / Legal Aptitude
   • Logical Reasoning
   • General Knowledge & Current Affairs
   • Quantitative Techniques (Elementary Mathematics - usually Class 10 level)
5. Application & Counselling:
   • Register and apply for the relevant entrance exams well before their deadlines.
   • Appear for the exams.
   • Based on your rank/score, participate in the counselling process for seat allocation in different colleges.
6. Enrollment & Study: Once allotted a seat, complete the admission formalities and begin your 5-year integrated course. This course combines subjects from your chosen graduation stream (like Arts, Commerce, etc.) for the initial years, alongside core law subjects throughout the five years.
7. After Graduation: Upon successfully completing the 5-year course, you receive an integrated degree (e.g., B.A. LLB Hons.). To practice law in court, you must then enroll with your respective State Bar Council and pass the All India Bar Examination (AIBE).

Hope it helps.