Dr. Potdar, the technique should work fine but you do need to define your variables.  One question I have - how do you define 'Religious Tourism?'  Are you concerned only with those who go to a site/destination for the religious experience, or are you combining these with the tourists who visit simply because it is a known (or beautiful) destination.  Can you separate these groups, or should you?  The purpose of their visit is certainly different, and the impact of changes could affect one type of tourism more than the other.

You can come to Braga, during the Holly Week, which can be considered a religious destination.

Since development is your concern the index should capture the attributes associated with religious fervour that the destination embodies. And I do agree that disentangling the religious from the secular; the sacred from the mundane, is going to be a challenge. Partly because measurements are going to be relative, but also because a lot of it is subjective and experiential in nature. The space-place transformative relation that features largely in a religious tourism setting may be hard to quantify. I make reference to this as a kind of superimposition of spatial and experiential dimensions. There may be range of values for the composite index, for which it is indicative, that this threshold is being reached or its a departure from it. 

As is the case for the consumer price index, a composite index of prices based on a reference basket of goods, the composite index for religious tourism may require a "basket of must -sees" that will give the most representative weightage in the spirit of seriousness.

Article Sartre's Spirit of Seriousness and the Bad Faith of “Must-See” Tourism

Conference Paper LIMINALITY AND AUTHENTICITY: EXPERIENTIAL AND SPATIAL SUPERI...

Dear Meena,

From what I understand, the composite index is a numerical technical. So, if you want use the composite index in the study of religious tourism, specifically to evaluate developed and undeveloped destination, you should check databases to arrival to maritime, air and land ports, in each selected destination. And contrast these data with information from monasterior or holy places in each destination.

I hope this will help.

Many thanks

http://www.jstor.org/stable/27527024?seq=1#page_scan_tab_contents

Luis has recommendations that work for some types of 'travel,' but it all depends on the exact type of tourism, and where the tourists are coming from.  If you are looking at the Pilgrimage to Mecca, the data Luis recommends can give good estimates of numbers (but not necessarily spending).  If you are looking to see if visitors from other cities in India are visiting another city to see their holy shrines, you will need a very different method to collect data on these religious visitors. For us to help further, could you provide us with more information on the types of religious tourism you want to study, and in what geographic areas of the world?  For example, are you comparing different holy sites within a single country, pulling local (or international) visitors, or comparing sites across a region (or the world)?

I agree with Abhishek Raj

THANKS TO ALL OF U

http://www.ijsrp.org/research-paper-0912/ijsrp-p0982.pdf

http://www.opf.slu.cz/aak/2011/01/antousova.pdf

http://www.coris.uniroma1.it/sites/default/files/14.25.20_Urban%20tourism%20researchRecentprogressandcurrentparadoxes.pdf