Hi Rajat
I'm not an Admissions Expert, nor am I an Expert in any of the Schools that you've listed. Many Schools have publicly stated that they do not factor in an Applicant's IR score during the admissions process, so you likely have nothing to worry about there. 16 months of work experience is on the 'lighter' side though - Schools tend to want 2-5 (or 3-5) years of experience. There are always exceptions, of course - especially if your work experience is suitably interesting/special.
These are important questions, so you should post them in the Admissions Forum.
GMAT assassins aren't born, they're made,
Rich