Income tax return for f.y.2017-18

Penalty upto to Rs.5,000/- will be charged if you file return post Jul 31, 2018

IS IT NOT THAT IT CANNOT BE FILED AFTER DUE DATE i.e. AFTER 31ST JULY 2018? 

you can file belated return after 31st july 2018 with penalty of ₹5000 or ₹1000 as the case may be. You can file belated return for AY 2018-19 till 31st March 2019m you can go through this short blog for details:
https://idealconsultax.blogspot.com/2018/06/penalty-on-late-filing-of-income-tax.H T M L

THANK YOU FOR INFORMATION