yr sory bro!!
ur applying for bachelors level diplomma i guess, the VO is looking at ur last education level i.e 12th marks ...
becoz they r low he is concluded that u might be competent enuf to take up this course.
I would do two things if i were you , firstly
1) I would rite a SOP explaing the reasons why you scored less , you can give family reasons etc , describe you started to take
ur careeer seriously nd are loking foward to turn things around with this oppurtunity.
2) Recommendation letters from your school teachers describing that the marks dont reflect your level etc etc.
3) Work hard and get a good IELTS score something like 7 -8 .
4) I would give a universal accepted exam like SAT , score very well , this would a sense of confidence to the VO
that you have a good IQ & are competent enuf to complete the course in canada.
I hardly believe that adding ITR's or property would make any impact if u reapply, the first thing u have to work on is
your academics bro!!! You gotta prove u r now serious for studies and you have it in you to complete the course you opted for.
Also if you took commerce in the 12th make sure you apply to a commerce related Diplomma , if you took up science make sure you are
taking up a science related diplomma
Play to your streength , if you scored best in say computers or chemisty or physics (the best you got in ur 12th) , pick up a course
that is related to ur stength , you can mention this ur SOP as well.....
All the best ....