In pbm 1.8 version, I could see Incremental backups are supported in logical type but in pbm 2.0.5 version, I am seeing incremental backups are not supported in logical type and it is supported only in the physical. May I know the reason?
Also, Can I use 1.8 version still for production deployment?
Hi, 1.8 is very old, I suggest you migrate to a newer release and start using physical backups, which are much faster. You can still do incrementals with physical backups
Thanks Ivan. I am going through the physical type now.
I could see we have to use psmdb to work with pbm physical type, can we make use of existing mongodb server cursors?
Yes, you will need to use psmdb for that. Luckily it is a drop-in replacement so should be easy to migrate 
I have a production setup with mongodb enterprise edition and I am trying to use pbm utility for backup and restore. For physical type in pbm, it requires psmdb, so if I install psmdb, will it conflict mongodb enterprise edition?
I understand. In that case you are limited to the logical backup for now, as you cannot run both MongoDB Enterprise and Percona distribution together. I suggest you give Percona a shot. There are no license costs and it provides similar feature set to Mongo Enterprise.