How to find smallest length between hit point and vertices

I wrote code for deforming object by raycast, but something I don't know so my code doesn't work. I wanted to find closest point to hit.point by finding smallest length between hit.point and each vertices but then at least inside radius.

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class LaserGunRayCast : MonoBehaviour
 {
     //raycast
     public float _LaserLenght = 100;
     public float _MaxDistanceCollision = 1000;
     RaycastHit hit;
     float _duration = 10.0f;
     //
     new Vector3 _LaserStart;
     new Vector3 _LaserEnd;
     Color _LaserColor = Color.red;
     public float duration = 5f;
     //
     public float force = 0.1f;
     //public float forceOffset = 0.1f;
     Vector3 _Lenght; 
     //
     void Start()
     { 
     }
 
     void Update()
     {
         Ray ray = GetComponent<Camera>().ScreenPointToRay(Input.mousePosition);
         Debug.DrawRay(ray.origin , ray.direction * _LaserLenght,Color.blue);
         if (Physics.Raycast(ray.origin, ray.direction * _LaserLenght, out hit, _MaxDistanceCollision))
         {
             if(Input.GetButtonDown("Fire1"))
             {
             Debug.DrawRay(ray.origin , ray.direction * _LaserLenght,Color.red);
             //ShowLaser(_LaserStart,_LaserEnd,_LaserColor,duration);
             Deformation(hit);
             }
         }
         
     }
     void ShowLaser(Vector3 start, Vector3 end, Color color, float duration)
     {
         GameObject _Laser_GameObject = new GameObject();
 
         _Laser_GameObject.AddComponent<LineRenderer>();
 
         LineRenderer _Laser = _Laser_GameObject.GetComponent<LineRenderer>();
 
         _Laser.SetColors(color, color);
 
         _Laser.SetWidth(0.5f, 0.5f);
 
         _Laser.material = new Material(Shader.Find("Unlit/NewUnlitShader"));
         Debug.Log(_Laser.material);
 
         Vector3 NewTranformPos = new Vector3(transform.position.x + 0.2f,transform.position.y - 0.2f,transform.position.z);
         _Laser.SetPosition(0,NewTranformPos);
         _Laser.SetPosition(1,transform.TransformDirection(Vector3.forward) * 10);
 
         GameObject.Destroy(_Laser_GameObject,duration);
     }
     void Deformation(RaycastHit hit)
     {
         Mesh _deformingMesh = hit.collider.gameObject.GetComponent<MeshFilter>().mesh;
 
         GameObject _GameObjectDeformingMesh = hit.collider.gameObject;
 
         Rigidbody _DeformRigidbody = hit.collider.gameObject.GetComponent<Rigidbody>();
 
         //_DeformRigidbody.AddForce(transform.up * 2f);
         
 
         Vector3[] _MeshVertices = _deformingMesh.vertices; 
         //
         Vector3[] _MeshNormals = _deformingMesh.normals;
 
         int[] _MeshTriangles = _deformingMesh.triangles;
 
     //problems begins right here
         int i;
         decimal _LenghtclosestVertice = 914337593543950333;
         int _IndexClosestVertice = 0;
         int _radius = 10;
         
         for (i = 0; i < _MeshVertices.Length; i++)
         {
        
             if(_radius > (decimal)Vector3.Distance(hit.point,_MeshVertices[i]))
             {
             _MeshVertices[i] -= hit.normal.normalized * force; 
             }
             Debug.DrawRay(hit.point,hit.normal,Color.green,duration);
         }

         _deformingMesh.vertices = _MeshVertices;
         _deformingMesh.RecalculateNormals();
         _deformingMesh.RecalculateBounds();
         
         Destroy(_GameObjectDeformingMesh.GetComponent<MeshCollider>());
         _GameObjectDeformingMesh.AddComponent<MeshCollider>().convex = true;
     }
 }