How we can publish multiple applications on same VIP with same port & same irule?

Are you 100% sure your host names are just plain abc.com and xyz.com? That is, they are not something like www.abc.com or application.xyz.com?

You should also be doing a 'string tolower' on your HTTP::uri match, same as you're doing on your HTTP::host match. And there's no need for the 'then' after your if statements.

If after you make these changes and the iRule still doesn't work, please describe exactly what isn't working.

Try this:

when HTTP_REQUEST {
SSL::disable
if { [string tolower [HTTP::host]] equals "abc.com" } {
    if { [string tolower[HTTP::uri]] contains "cvapweb" } {
            pool abc_9090 
    } 
    else {
            pool abc_8080
    }
}

elseif { [string tolower [HTTP::host]] equals "xyz.com" } {
    if { [string tolower [HTTP::uri]] contains "cvapweb" } {
            pool xyz_9090
    }
    else {
            pool xyz_9090
    }
}
}

Try this:

when HTTP_REQUEST {
    switch [string tolower [HTTP::host]] {
        "abc.com" {
            if { [string tolower [HTTP::uri]] contains "cvapweb" } {
                pool abc_9090
            } else {
                pool abc_8080
            }
        }
        "xyz.com" {
            if { [string tolower [HTTP::uri]] contains "cvapweb" } {
                pool xyz_9090
            } else {
                pool xyz_8080
            }
        }
    }
}

Not sure why you're using SSL::disable in your original iRule. Using it in an HTTP_REQUEST (OSI layer 7) suggests that you want to disable server side SSL, but if none of the downstream pools are SSL, and you don't have an SSL profile applied to the VIP, then you don't need this command.

At this point I'd recommend some logging:

when HTTP_REQUEST {    
    log local0. "Incoming host: [HTTP::host]"        
    log local0. "Incoming URI: [HTTP::uri]"
    switch [string tolower [HTTP::host]] {
        "abc.com" {            
            log local0. "Catching abc.com"
            if { [string tolower [HTTP::uri]] contains "cvapweb" } {                
                log local0. "abc.com URI contains cvapweb"
                pool abc_9090
            } else {                
                log local0. "abc.com default pool"
                pool abc_8080
            }
        }
        "xyz.com" {            
            log local0. "Catching xyz.com"
            if { [string tolower [HTTP::uri]] contains "cvapweb" } {                
                log local0. "xyz.com URI contains cvapweb"
                pool xyz_9090
            } else {                
                log local0. "xyz.com default pool"
                pool xyz_8080
            }
        }
    }
}    

Tail the LTM log and test again.

tail -f /var/log/ltm    

You may be surprised by what you find.

Hello Guys, I need help on same scenario but working on https. /

example :-  url  https://hello.abc.com  will be go to Pool hello.abc.com 

       if url https://hi.abc.com will go to hi.abc.com 

          where VIP is same with https port for hello.abc.com & hi.abc.com 

Hello mates, I need help on below scenario working on https. /

example :- if url https://hello.abc.com will be go to Pool :- hello.abc.com

   if url https://hi.abc.com will go to Pool :- hi.abc.com 

      where VIP is same with https port for https://hello.abc.com & https://hi.abc.com