HTACCESS Issue : Sitemap.xml giving error when access

Server : Shared Bigrock
Trying to Rewrite sitemap.php to sitemap.xml
But when going to access https://www.indiaztour.com/sitemap.xml (Showing blank in firefox and HTTP ERROR 500 in chrome).

Note : Working fine on local server (xampp).

My HTACCESS Code is as below

Options +FollowSymLinks -MultiViews
RewriteEngine on
# ensure www.
RewriteCond %{HTTP_HOST} !^www\. [NC]
RewriteRule ^ https://www.%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
# ensure https
RewriteCond %{HTTP:X-Forwarded-Proto} !https
RewriteCond %{HTTPS} off
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
RewriteRule places-(.*)\.php$ places.php?page=$1 [NC,L]
RewriteRule blog-(.*)\.php$ blog.php?page=$1 [NC,L]
Rewriterule sitemap.xml$ sitemap.php [L]
Rewriterule sitemap1.xml$ sitemap1.php [L]
Rewriterule sitemap2.xml$ sitemap2.php [L]

Code (markup):

I am using same code to one of our website at VPS and working fine but not at shared server. Please guide me that what i am missing here.

I am trying to find error and put code also at sitemap.php

error_reporting(E_ALL);
ini_set('display_errors', 1);
header('Content-Type: text/xml');

PHP:

But seems like its not entering to page ..... because showing either blank page or 500 error only.