When aniline is nitrated with nitrating mixture in ice cold condition , the major product obtained is- a)ORTHO, b)PARA, c)META-nitro anniline or some something else? Please help.

I think it would be o-nitro-anniline (as in this case there is no mention of acetylation) there is no queation of blocking the ortho side by bulkier group.In addition to that in ortho position H-bonding confers additional stability.So I have done it as o-nitro anniline.Rest depends on WBJEEB

Para will be major product!
Always remember that Only and only i case of Methyl attached to benzene will  form ortho as major product on chlorination,nitration or Hbonding otherwise para will be always the major product formed! 

can you explain it with reason?

I do agree with sir,s  reason as "ice cold condition can never change the mechanism of a chemical reaction".However as a result of this,the rate of this reaction will become extremely slow and So "papa" will be the most easily formed & major product in this reaction.(NCERT TEXTBOOK-AMMINE chapter)  

Para will be major product!
Always remember that Only and only i case of Methyl attached to benzene will  form ortho as major product on chlorination,nitration or Hbonding otherwise para will be always the major product formed