How to make plane as tree leaf (2 side plane) like in GTA Vice City?

If you intend no wind Animation on your tree this shader should work fine..

 Shader "CustomShaders/DiffuseCutout" {
 Properties {
     _Cutoff("Alpha Cutout",Range(0,1)) = 0.15
     _Color ("Main Color", Color) = (1,1,1,1)
     _MainTex ("Base (RGB)", 2D) = "white" {}
     _BumpMap ("Normalmap", 2D) = "bump" {}
 }
 
 SubShader {
     Tags { "RenderType"="Opaque" }
     LOD 400
     Cull off
 
 CGPROGRAM
 #pragma surface surf Lambert addshadow
 
 sampler2D _MainTex;
 sampler2D _BumpMap;
 fixed4 _Color;
 fixed _Cutoff;
 
 struct Input {
     float2 uv_MainTex;
     float2 uv_BumpMap;
 };
 
 void surf (Input IN, inout SurfaceOutput o) {
     fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
     o.Albedo = c.rgb;
     o.Alpha = c.a;
     o.Normal = UnpackNormal(tex2D(_BumpMap, IN.uv_BumpMap));
     clip(tex2D(_MainTex, IN.uv_MainTex).a * c.a - _Cutoff);
 
 }
 ENDCG
 }
 
 FallBack "Legacy Shaders/Transparent/Cutout/BumpedDiffuse"
 }