What is Minimum percentage required in graduation to appear for IAS exam?

There is no particular requirement for percentage of marks in Graduation to appear for IAS exam. You must pass graduation degree examination ..

Here I am giving you information about required Minimum qualifications for Indian administrative service examination organized by Union public service commission below :

IAS exam Eligibility Criteria:
You have to pass graduation in any discipline from a well recognized university.

Age limit :
OBC candidate age limit maximum : 33 years.
The candidate must be between 21-30 years of age.
SC/ST have 5 years of age relaxation.

IAS Preliminary Examination Syllabus
Syllabus of Paper I -(200 marks) Duration : Two hours
Current events of national and international importance.
History of India and Indian National Movement.
Indian and World Geography-Physical, Social, Economic.
Geography of India and the World.
Indian Polity and Governance-Constitution, Political.
System, Panchayati Raj, Public Policy, Rights Issues, etc.
Economic and Social Development-Sustainable.
Development, Poverty, Inclusion, Demographics, Social.
Sector Initiatives, etc.
General issues on Environmental ecology, Bio-diversity and Climate Change - that do not require subject specialization and Climate Change - that do not require subject specialization.

Syllabus for Paper II-(200 marks) Duration: Two hours
Interpersonal skills including communication skills;
Logical reasoning and analytical ability
Decision making and problem solving
General mental ability
Basic numeracy (numbers and their relations, orders of magnitude, etc.) (Class X level), Data interpretation (charts, graphs, tables, data sufficiency etc. - Class X level)