InfoPath Dev

Before publishing only I have done the modifications for the data connection by removing it from offline mode even this doesn't helped

I could see in the form files that there were still files intended for including offline data - apparently changing that setting didn't clean up the form files. I've manually removed them and the references to them in this copy of the form - maybe try this one, but I'd verify the data connections work first. Did you originally design this form? If so, did you start from a new, blank template in InfoPath?

The issue is same with this form also.I didn't designed this form

I'm out of ideas. I'm assuming the form has not been browser compatible in the past? You will probably just have to start disabling logic / removing defaults until you are able to get the form to work in the browser.

As the form has published many times so in the site columns i can see many duplicated columns so how can i remove the duplicate columns and keep the right one

That is always a bit of a mess. I'd guess that the form isn't currently in use, since you hadn't been able to get it published as a browser form? If so - I'd probably remove the content type and all of the columns, then publish it up again.

when i tried to delete the columns form the form library i see some of the duplicated columns are not highlighted and even i am not able to delete those duplicated columns.can you suggest any other way to delete them.

when i tried to delete the content type i am getting the following error.But i have checked all the list i didn't find any thing connected to this content type