For beginners who are completely new to the domain of economics, go through NCERTs book for gaining the understanding of the fundamentals, the content is written is easy to understand language, and there are many good creators in YouTube as well who have uploaded these lessons as well, so if you're someone who feel more comfortable in understanding concepts through audio-video medium, you can refer this, other than that personally I have found Indian Economy by Ramesh Singh to be a great book as all the topics are covered in elaborative manner, and the language too is easy to comprehend, you can also refer Indian Economy by Sanjiv Verma which is equally a good option, other than this supplement your preparation with budget and economic survey, you can go through yojana magazine, and the economic edition of pratiyogita darpan too is quite good, if you have time you can go through that, even the regular book which comes out every month is pretty good for preparation of any compeitiive exam.
Some of the best books for Indian economy for UPSC preparation are:
1. Indian economic development
2. NCERT of class 11th Introductory
3. Macroeconomics Class 12th NCERT
4. Indian economy by Sanjiv Verma
5. Indian economy by Ramesh Singh
6. Economic survey (latest)
7. The Hindu or Indian express newspaper
8. Economic development and policies in India- Jain and Ohri
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Hope this helps, all the best.