We are fetching some value from DB and trying to show it in Message field in one

Have you tried setting the conf.suite.DATA_CAP_PARAGRAPHS property in custom.properties to a higher number

yes we have tried it increasing till conf.suite.DATA_CAP_PARAGRAPHS=50000, but still no luck.

1. Did you restart the application server after the change?
2. You're saying the issue is with more than 100,000 characaters but you set the property to 50, 000. That means this value is still smaller:

50,000 < 100,000

Thanks for your reply Ed.

1)Yes, we have started the application server.

2)If we increase value to 120000, is it going to affect performance of the server by any way?

These limits are established to prevent performance issues. I suggest you review your approach, maybe you can use one of the Export to Excel plug-ins out there in the Shared Components so the end user can download the data instead of seeing it in a form.

If you still want to increase the value to 120K then you need to do performance testing, but I'd definitely suggest not to use quite high value.