Class 11

A major chunk of the entrance exam syllabus for BTech Mechanical Engineering is based on the Class 11 and Class 12 class topics, and thus it is highly recommended to study the 11 and 12 NCERT books that serve as a common source of some direct questions in the entrance exams. Popular exams like JEE Main and MHT CET syllabus give a lot of weightage to Class 11 and 12 concepts of Physics, Mathematics, and Chemistry. 

Till Class 10, we studied every subject on the base level, but from Class 11, the streams are segregated and allotted to students to level up their education. If you opt for Humanities in Class 11, and you have a Political Science subject, there might be chances that you'll gain a deeper knowledge of the subject and explore new sub-topics.
That's the reason why most students find Class 11 subjects relatively tougher.

Following documents are required:

1. Class 10 marksheet
2. School leaving certificate 
3. Duly filled admission form 
4. FYJC admission Allotment Letter 
5. Passport size photo
6. Income certificate and caste certificate (if you are under any quota)

Yes, you may start CUET preparation from class 11th. It gives you extra time to study slowly and recognize subjects properly.

Read NCERT books, practice english and reasoning questions.

This will assist you stay beforehand and experience much less strain in class 12th.

Make a each day plan and study frequently.

You are not eligible for DASA. To apply through DASA or CIWG, a student must have completed both 11th and 12th abroad in the last 8 years. Since you did 11th–12th in India and only 7th–8th in Dubai, you don't meet the eligibility—even if your father worked abroad.

Yes, there is Junior College at St. Mira's college which is equivalent to Class 11th and 12th. The courses covered are

Arts

Commerce

Science 

To study law after completing Class 12, you can complete school with any stream. Then, sit for entrance tests - CLAT, AILET, or state-based entrance tests for 5-year integrated law courses (e.g., BA LLB). Preparation during Class 11-12 requires prior preparation in English, reasoning, legal aptitude, and current affairs well.

Well there is no entrance exam required for class 11th to AMU Aligarh. However, the Aligarh Muslim University accepts entrance exam for various courses including B.Com, BA LLB, M.Com, B.Sc, MBA, the university accepts entrance exam like Common University Entrance Test CUET UG & their own Aligarh Muslim University Entrance Test are required for admission whose admit cards were already released on 4th April and the exams are also conducted already. For more information you can visit the official website of college.