The app also contains Audio dictionary, Fun games, Helpline chats and other extra features apart from the lessons. If you EXCLUDE the OTHER things, it's entirely possible in that budget.
Relevant Skills and Experience
Android, Java, SQLite, MySQL, AWS, GCP, Firebase.
Proposed Milestones
₹3000 INR - Sketch + wireframe + template
₹9222 INR - App development
The contents/lessons must be provided by the client.