Income tax return

no.. you can't file for a. y. 2017-18 & 2018-19 unless the delay is condoned by your jurisdictional CIT for want of refund or loss to be carried forward.

Sec 119(2)b is section for applying to the AO for condition of delay.

Condonation application u/s.119(2)(b) to be filed before jurisdictional CIT

how to file condonation application

lokesh you can file by logging into your efiling website.
there is an option for raising query.

It should be filed manually before your jurisdictional CIT

how to file manually

@ Lokesh

In normal course you can not file.

However you can apply to your jurisdictional AO or online e-filing site (under my accounts - Request) 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.