Scope of Power to IT Authority

If the delay in filing ITR is condoned by jurisdictional CIT then yes

It means some Banking officers are right in saying that we are able to file your itr for last three p.y years

In normal course you can not file.

However you can apply to your jurisdictional CIT under 119(2)(b) for condonation of delay for each assessment year with genuine reasons and after it's approval you can file return for those Assessment years.

Approvals are given by CIT only for Specified reasons viz TDS claim, loss return, loan purpose etc