how can i set object list in default input value

1. Since you use different label and value attributes, you need to use getOptionLabel of react-select component to identify the label.
2. Your values do not include AMS, you need to control NNS instead of AMS in your second if/else of your changeList function.

The following code can be a valid example of setting default values on multi selectable Select component.

    import React, { Component, useState } from 'react';
    import Select from 'react-select';

    const MySelectComponent = () => {

      const [ListS, setListS] = useState({
        Sanctions: true,
        NNS: true,
        PEP: false,
      });

      const listType = [
        { value: "Sanctions", label: "Sanctions" },
        { value: "NNS", label: "AMS" },
        { value: "PEP", label: "PEP" },
      ];

      const changeList = (e) => {
      console.log("List s is.....", ListS);
      console.log("e here is", e);

      if (e.selected.find(({ value }) => value === "Sanctions")) {
        setListS((prev_state) => ({
          ...prev_state,
          Sanctions: true,
        }));
      } else {
        setListS((prev_state) => ({
          ...prev_state,
          Sanctions: false,
        }));
        //setSearchType({ value: "individual", label: "individual" });
      }

      if (e.selected.find(({ value }) => value === "NNS")) {
        setListS((prev_state) => ({
          ...prev_state,
          NNS: true,
        }));
      } else {
        setListS((prev_state) => ({
          ...prev_state,
          NNS: false,
        }));
      }

      if (e.selected.find(({ value }) => value === "PEP")) {
        setListS((prev_state) => ({
          ...prev_state,
          PEP: true,
        }));
      } else {
        setListS((prev_state) => ({
          ...prev_state,
          PEP: false,
        }));
      }
      };
      const selectedValueKeysFiltered = Object.keys(ListS).filter((sv) => {
          return ListS[sv];
      });

      const selectedValue = selectedValueKeysFiltered.map((svk) => {
        return listType.find(lt => lt.value === svk);
      });

      return <Select
        getOptionLabel={option => {return `${option.label}`}}
         options={listType}
         name="sanctionList"
         placeholder="Select"
         isMulti
         styles={{
           multiValueLabel: (base) => ({
             ...base,
             backgroundColor: "#0bb7a7",
             color: "white",
             fontSize: "0.8vw",
             borderRadius: 5,
           }),
           control: (data) => ({
             ...data,
             fontFamily: "Montserrat",
             fontSize: "0.8vw",
             borderColor: "#adadad",
           }),
           menu: (data) => ({
             ...data,
             fontFamily: "Montserrat",
             fontSize: "0.8vw",
           }),
         }}
           // isDisabled={!ListSel}
           value={selectedValue}
         onChange={(e) => changeList({ selected: e })}
         theme={(theme) => ({
           ...theme,
           colors: {
             ...theme.colors,
             text: "black",
             primary25: "#d6fdf7",
             primary: "#0bb7a7",
             primary50: "#d6fdf7",
           },
         })}
       ></Select>;
    };

    export default MySelectComponent;