Product based company

Hi

I am from tcs. 6 years of experience. I have applied multiple times to JP Morgan, oracle , philips , evey other companies . I have requested for referrals and some refer me for that role. I don't know I didnot get call from any of these companies . My resume is good. I don't know where I lag. If anyone from any these companies please let me know how you got selected and what strategy you have used for thus preparation. Seriously so stuck here. Any certificate needed?