Add a LTM VIP to GTM pool

Hello Parveen this is not something that can be answered in a post. If you are new then you need to read up on GTM, how GTM checks LTM's for health related information ect if you are looking for everything to be setup from scratch. Now if you have any previous F5 admin already configured GTM and LTM in your environment and you are looking just to create a wideip then you can use the below. Change the naming convention as you need

modify server  virtual-servers add {  { destination }} datacenter 
modify server  virtual-servers add {  {destination }} datacenter 
create pool  members add { : :} load-balancing-mode global-availability
create wideip ApplicationName.com pools add {  } ipv6-no-error-response enabled

I would recommend following crodriguez advice if you are new to GTM.