Hello,

First of to become IAS, IPS, or IFS if you meant Indian Foreign Service as a designation will be assigned to you as per the rank you secure in UPSC exam, IAS is the topmost preferred post by candidates, as it offers diverse opportunities in terms of work than other job profile, anyway since you're still in graduation, first of all be acquainted with UPSC syllabus, learn it by heart, it's important to know what to read and what to skip as it's such an extensive syllabus, and then start reading newspaper on a daily basis, and this should continue till your day of interview as it has such importance, focus on news of national and international importance, economy, science and technology,  editorial, basically all the relevant details, and when it comes to study materials go through NCERT first as it will build your foundation strong, Some of the recommended books are as follows;

For Prelims, in case of History refer NCERT Class XI and XII/India's Struggle for Independence by Bipin Chandra, For Indian Culture, refer art and culture by Nitin Singhania, for Geography  refer NCERT Class VI to XII/GC Leong's Physical Geography/World Atlas, for Economics  refer NCERT Class XI/Indian Economy by Ramesh Singh, for International Relations & Polity ;NCERT XII Political Science with current affairs/Indian Polity by Laxmikanth, for CSAT ;Verbal and Non-Verbal Reasoning by RS Agarwal/M Tyra's Quicker Maths

For  Mains Exam, got through the following for four General Studies Paper;

GS I -  History , Class XI NCERT book with India's struggle for Independence by Bipin Chandra,India after Independence by Bipan Chandra,History of Medieval India by Satish Chandra

In case of Geography refer World Geography and Geography of India by Majid Hussain, GC Leong's Physical and Human Geography with NCERT Class XI book.

For GS II - Polity and International Relations , refer Indian Polity by Lamikanth,India's Foreign Policy by Rajiv Sikri

For GS III - For Economics refer Indian Economy by Ramesh Singh, read ARC report along with Economic Survey and Fiscal Budget.

For GS IV - For Ethics refer a book named Lexicon by Niraj Kumar, also you can go through study material of IGNOU.

Always remember to  keep your resources minimal, read one book many a times instead of many a book one time, revision is the key here as UPSC has got such humongous syllabus, hence it's important you revise regularly and refer limited books.

Go through previous year papers, and apply mock papers that's available in the sites exclusively dedicated to UPSC preparation, and practice answer writing in advance as writing mains is huge task, you can refer topper's answer sheets that is available online in few of the sites.