Has it flowered in the last year though? I know you're not getting fruit, but is it flowering?

Does the vine continue to grow well?
Also, is it in the ground or a pot?

A passiflora enthusiast told me to use a high potassium feed on them.

No flowers Bamboo.! yes its growing well but in a pot.Why potassium ? , phosphorous is required more to encourage flowering i guess.

No idea why potassium - I was simply passing on his advice.
If it is growing well in a pot it would seem to be happy. So why should it flower? Fruits are just seed production organs to ensure the survival of the species. So I would maybe switch to a high potassium feed, or stop feeding for a while.
Do you know which species you have, and where in India are you? Is your climate compatible with the plants native habitat?

its been a very mild spring/winter to . maybe putting it in the ground direct will help as some of these get realy big .

Potassium encourages flowering, that's why - also known as 'potash', and represented by the last number in the NPK levels - K means potassium, so that number needs to be high. However, I suspect its the pot that's the problem - you need to plant it out so it can grow properly and then flower and fruit.
Meanie: this version of Passiflora is grown for its fruits rather than its flowers, as a cropping plant, so encouraging it to flower is a good idea.

great minds bamboo x .

Bamboo - I kinda understood that, but strange that he stuck to just the one fertiliser (you know how enthusiasts can be!).

Just found this link in my bookmarks which may be of use Kushal.................

http://www.passionflow.co.uk/passion-flower-passiflora-plant-food-fertilizer.htm

Well yes, but the fertilizer was balanced, at least, with an even NPK, Won't be shortage of food causing trouble, but might well be lack of root room for the plant to grow properly.

Over feeding of some members of the pea family can cause them not to bloom - could that be the issue?
OH's Passiflora antioquensis grew and bloomed really well in just a 3 litre pot (and has made it through the winter outdoors too!).

Not a member of the pea family though, Passiflora. You know what they say, look at the simple things first - I think its being contained that's the problem.

I know that it's not a member of the pea family, but being contained doesn't usually stop Passiflora either. Large plants can be grown well in 25cm pots as they have fairly small root systems.
(ps - not picking a fight, just trying to be helpful. Been reading up a lot on them as I now have a Passiflora alata to try to outdo her P.antioquensis!)

Oh, okay, I thought you didn't know whether it was in the pea family or not! I think the difference with this one is the fact its a fruiting plant rather than just an ornamental one, and in order to produce decent fruit, it needs better conditions.

BOOO lol