You asked: "After getting accepted by the IRS how long will it take to get the return through direct deposit ?"
The IRS says 9 out of 10 filers who efile and choose direct deposit will get their refunds within 21 days. That still leaves a number of people who do not. Some returns take longer for additional processing due to specific items in the return. Some are pulled at random for more thorough investigation.
NOTE: By law the IRS will not start issuing a refund on tax returns claiming the Earned Income Tax Credit or Additional Child Tax Credit until February 15. So filers with those credits likely will not see refunds until late February or possibly early March in some cases.