Introduction:
NCERT textbooks are considered to be the foundation for UPSC preparation, including modern history. However, it is possible to skip NCERT for modern history prelims if certain conditions are met. This response will explain in detail whether it is advisable to skip NCERT for modern history prelims.

Understanding the Importance of NCERT:
1. Comprehensive Coverage: NCERT textbooks provide a comprehensive understanding of the subject matter, covering all the important aspects of modern history.
2. Simplified Language: NCERT textbooks are written in a simple and easy-to-understand language, making it accessible to all aspirants.
3. Reliable Information: NCERT textbooks are considered reliable sources of information as they are developed by subject matter experts and approved by educational authorities.

Reasons to Skip NCERT for Modern History:
While NCERT textbooks are highly recommended for UPSC preparation, there are a few reasons why one might consider skipping them for modern history prelims.

1. Time Constraints: NCERT textbooks can be time-consuming to read, especially for candidates who are preparing for multiple subjects simultaneously. Skipping NCERT for modern history can allow candidates to allocate more time to other subjects or revision.
2. Overlapping Content: Modern history topics covered in NCERT textbooks may also be covered in other reference books or study materials. If candidates have already studied modern history from alternative sources, they may choose to skip NCERT.
3. Familiarity with the Topic: If candidates have a strong background or prior knowledge of modern history, they may be able to confidently skip NCERT and focus on other study materials.

Alternative Resources:
1. Spectrum's "A Brief History of Modern India" by Rajiv Ahir is a popular book that covers modern history comprehensively and is widely recommended by UPSC toppers.
2. Bipan Chandra's "India's Struggle for Independence" is another recommended book that provides detailed insights into modern history.
3. Online platforms like EduRev offer comprehensive study materials, including notes, quizzes, and previous year question papers, which can be used as an alternative to NCERT.

Conclusion:
While NCERT textbooks are highly recommended for UPSC preparation, candidates can consider skipping them for modern history prelims if they have time constraints, already covered the topics from alternative sources, or possess a strong background in the subject. However, it is important to choose reliable alternative resources that cover the syllabus comprehensively.