there are 3 papers in ashok leyland. 2 from technical and 1 from non-tech. you shud go thru any objective book for technical. they will cover all the topics in 2 papers even engg. drawing also.
for 1st technical paper- 25 min 50 ques
2nd technical paper- 30 min 50 ques
for non-tech 30 min 60 ques..
i think most difficult portion is non-tech, covering english and r.s. agarwal reasoning.
so go through the syllabi and r.s.agarwal and for english go thru any book like manohar prasad or barrons....
waise non-tech portion will be ceciding for toppers. so b careful in that.
for interview,if you are from btech.they will ask you from your core subjects like thermal,automobile and i.c.engines or ur area of interest. they will also ask about ur training(vocational) and ur project.
if u r frm mtech,they will ask for ur thesis.
the knowledge of software CATIA will be helpful because this is an automobile company and all automobile companies use CATIA for designing.