Thanks ,

Now i used the follow thing ,

server {
listen 192.168.1.150:80;
server_name srinivas.walkingtree.in;
location / {

proxy_pass http://192.168.1.203/joomla/;
proxy_redirect off;

proxy_set_header Host $host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

client_max_body_size 10m;
client_body_buffer_size 128k;

proxy_connect_timeout 90;
proxy_send_timeout 90;
proxy_read_timeout 90;

proxy_buffer_size 4k;
proxy_buffers 4 32k;
proxy_busy_buffers_size 64k;
proxy_temp_file_write_size 64k;
}
}

when i click on products ,
http://srinivas.walkingtree.in/joomla/index.php/products

error:

Not Found
The requested URL /joomla/joomla/index.php/products was not found on this server.