Hey Vsanjos.

You can easily prepare for NATA in few months, provided you are consistent.

Mainly three things are required -

Drawing

Aptitude

Maths

DRAWING

For there are a plently of options on youtube, which can teach you how to draw in perspective.

APTITUDE

Following would be my suggestions -

Research and follow the following topics everyday -

Important Building in India and the World

3d objects and their plans and elevations

Important architects of India and the world

Mirror Images

Common Building materials and terminology

Common Architectural Terminology

Logical and reasoning ability questions

General maths questions like area, volume, speed distance and time etc.

MATHS

For maths follow CBSE books, the NATA maths paper is very easy.

DONT ATTEMPT GUESS ANSWERS, THERE IS NO NEGATIVE MARKING , BUT as u attempt guesses each wrong answer with lower the marking of next answer and so on . A student with 15 right questions of high marks may score 54/100 and another with 25 correct answers of low marks question may score 30/100.

Hope this serves your query. Please feel free to respond and ask further questions.

All the best.