Step 1 : Make the CSV file of object name and IP address in following format (filename =script1.csv)

name,ip-address
name1,xxx.xxx.xxx.xx
name1,xxx.xxx.xxx.xx
name1,xxx.xxx.xxx.xx

Login to the device through CLI
change the location to  tmp ( cd /tmp )
create a script file inside it ( vi Script1.csv )
paste the CSV file
to check whether the file is created or not paste (cat script.csv)
Run CSV file (mgmt_cli add host –batch script1.csv)
provide username and password

Step 2 : Make CSV file of Object group name and object name (filename = script2.csv)

name,members.add
groupname, name2
groupname, name2
groupname, name2

Login to device through CLI
change the location ot tmp ( cd /tmp )
create a script file inside it ( vi Script2.csv )
paste the csv file
to check weather the file is created of not paste (cat scrip2.csv)

mgmt_cli -r true login > session.id
mgmt_cli -s session.id set group -b script2.csv
mgmt_cli -s session.id publish
mgmt_cli -s session.id logout

If the locked session error is seen then try to publish and install the previous policies and logout/disconnect or takeover all the Read and write sessions and ten try Step 2

Refrences
https://www.youtube.com/watch?v=li4vRH63-_8
https://community.checkpoint.com/t5/Management/Format-of-csv-file-to-add-object-in-group/td-p/8987