Reflective floor?

Use an appropriate shader, such as this one:

 Shader "Custom/MirrorReflection"
 {
     Properties
     {
         _MainTex ("Base (RGB)", 2D) = "white" {}
         [HideInInspector] _ReflectionTex ("", 2D) = "white" {}
     }
     SubShader
     {
         Tags { "RenderType"="Opaque" }
         LOD 100
  
         Pass {
             CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
             #include "UnityCG.cginc"
             struct v2f
             {
                 float2 uv : TEXCOORD0;
                 float4 refl : TEXCOORD1;
                 float4 pos : SV_POSITION;
             };
             float4 _MainTex_ST;
             v2f vert(float4 pos : POSITION, float2 uv : TEXCOORD0)
             {
                 v2f o;
                 o.pos = mul (UNITY_MATRIX_MVP, pos);
                 o.uv = TRANSFORM_TEX(uv, _MainTex);
                 o.refl = ComputeScreenPos (o.pos);
                 return o;
             }
             sampler2D _MainTex;
             sampler2D _ReflectionTex;
             fixed4 frag(v2f i) : SV_Target
             {
                 fixed4 tex = tex2D(_MainTex, i.uv);
                 fixed4 refl = tex2Dproj(_ReflectionTex, UNITY_PROJ_COORD(i.refl));
                 return tex * refl;
             }
             ENDCG
         }
     }
 }