Auto populate the field value on the form

[is_12]

Hello community !

1. SSR will be associated with only one hence for all the standard SSRs product should be populated in Product offering and displayed in the portal.
2. For CSR, if the item is associated with single product model, then it should be populated in product offering and displayed in the portal. 
3. For Bespoke CSR/ Order Guide, if the product is associated and not multiple then populate the product offering and display in the portal else, don't populate the product offering instead add it in the description only. No need to display in portal as well.

SSR & CSR are the catalog item, 

There is the script which I have written for the 1 & 2 point it is working fine

but for the 3 point CSR item, one request will be having more than one ritm need to get those item model & product offering & populate in the description of the case 

So can anyone help me with the script modification, here is the snippet of code

 if (!current.product_offering) {

            gs.info("checking the product 93" + reqGr.sys_id);

            var reqch = new GlideRecord('sc_req_item');

            reqch.addEncodedQuery('request=' + reqGr.sys_id + '^cat_item.u_catalog_typeINSSR,CSR');

            reqch.query();

            gs.info("checking the product 96" + reqch.getRowCount());

            while (reqch.next()) {

                gs.info("checking the product 99" + reqch.sys_id);

                if (reqch.cat_item.model) {

                    gs.info("checking the product 101" + reqch.cat_item.model.model_number);

                    var poGR = new GlideRecord('sn_prd_pm_product_offering');

                    poGR.addQuery('external_id', reqch.cat_item.model.model_number);

                    poGR.query();

                    if (poGR.next()) {

                        if (reqch.cat_item.model.model_number == poGR.external_id) {

                            gs.info("checking the product 106" + poGR.external_id);

                            current.u_prod_offering = poGR.sys_id;

                            current.update();

                        }

                    }

                }

        }

    }

Thanks in Advance,  !..

[is_12]

@Chavan AP @Ankur Bawiskar @Rafael Batistot Need to check one thing related to the product offering, on the case we have the product offering field where as on the RITM & the Sc task, we do not have the product offering field on the form, only on the list it is available. So, can I auto populate the value from  case to RITM on list alone ?