I want to inform you that the AIEEE Exam has replaced by IIT JEE Main Exam.

There are 2 Papers in IIT JEE Main Exam:
Paper I: For BE/ B.Tech
Paper II: For B.Arch / B.Plan

So you have to apply for Paper II for admission in B.Architecture Course.

I am providing syllabus of Paper II of IIT JEE Main Exam for your reference:

IIT JEE Main Exam Paper II Syllabus

Mathematics
Relations and Functions; Sets, Complex Numbers, Matrices and Determinants; Quadratic Equations; Permutations and Combinations; Sequences and Series, Induction, Simple Applications of Binomial Theorem, Integral Calculus, Limit and Continuity, Differentiability, Differential Equation, Co-ordinate Geometry; Vector Algebra, Three Dimensional Geometry; Trigonometry, Statistics and Probability and Mathematical Reasoning.

Aptitude
Texture related Architecture, Awareness of build-environment, materials, objects, 3D objects visualizing from 2 D drawings, 3D objects visualization, mental ability and analytical reasoning.

Drawing Test
3 D observation, building elements and forms, colour texture, contrast and harmony, Drawing and Design of abstract or geometrical patterns and shapes in pencil, elevations and 3D views of objects, creating 2 D and 3 D compositions using given shapes and sketching of activities and scenes.