from 16

Form 16 is the certificate from your employer, in which details of TDS deducted by him is mentioned. So simply its just TDS form. You can view your complete TDS credit from all parties on efilling website (www.incometaxindiaefilling.gov.in), by viewing form 26AS. Login on that website, if not already registered then register as new assessee. after completing your login credentials you will get OTP on mobile and link on email, use it to login.
Now after login, under my account tab, click on view 26AS and follow the steps.

i want from 16a and 16b

Also these are given for any Deductor.....

i want from 16