How to score marks in aptitude and also how to do drawing in b arch

Mainly free hand drawing like surface texture, details of its components in suitable scale, Ordinary domestic or everyday life utilizable objects like equipment, furniture, etc.
Geometrical drawing containing different geometrical figures. Their side views, front views, top views etc you have to practice.
For aptitude, you can study general awareness and interest of famous architectural creations (within the country and outside, places and celebrities, architects, designers etc.) Three dimensional perception, building forms, and elements, colour texture, harmony, and contrast, Visualizingdifferent sides of three-dimensional objects etc.
You can check at-
http://engineering.careers360.com/articles/jee-main-paper-2-syllabus