We know neutron star is very densest in the universe and it weighs the thousand times of our Sun. And Black hole having strong gravitational pull not even light can escape From it . So , whose gravitational pull is greater ?
The black hole has greater pull.
If you stand beside a massive object (planet, star, black hole or anything else with mass) you will feel a gravitational pull, and unless you do something about it you will start to accelerate towards the object.
So the gravitational pull (or more precisely the gravitational acceleration) depends on two things: How massive the object is, and how far you are from its centre.
Neutron stars are all between about 1.2 and 3 times the mass of the sun, any larger and they become black holes. Objects that are believed to be black holes are know with masses of about 4 times the mass of the sun. A black hole can be of any mass, there is no known way for smaller black holes to form.
Now if you fix the distance (say 150 million km), then the gravitational pull depends only on the mass of the object. A neutron star can be at most about three times the mass of the sun, black holes are nearly all larger than that, so the gravitational pull of the black-hole is greater. But if you find a way to make a small black hole, then it would have lower mass and so less gravitational pull, at the same distance.
You can also look at surface gravity. Black holes don't have a proper surface, but you could use the event horizon instead. Here the answer is easy: The gravitational pull becomes infinite at the event horizon (from a certain point of view), Neutron stars have very strong, but not an infinitely strong pull so the gravitational pull of a black hole is greater than a neutron star.
Gravitational pull is determined by only two things: mass and distance.
The greater the mass, the greater the pull. The shorter the distance, the greater the pull.
At the same distance (measured to the center), objects with the same mass will exert the same gravitational pull, no matter what they are. A black hole, a neutron star, a normal star, a giant marshmallow - they all pull the same at the same distance if their masses are the same.
The only difference is this: normal stars are quite fluffy and bloated, you can't get too close to their center because pretty soon you'll run into their surface, and that's where the formula for the pull changes. So the maximum pull from a normal star is not too big, simply because you can't get "close enough" to the center.
Neutron stars are much more dense. You can get a lot closer to their center before you hit the surface. So at the same mass, a neutron star lets you get closer so as to generate a greater pull.
Black holes are the most dense of all. In theory you could get arbitrarily close to the center, because the BH is all in the center (sort of, not really, probably). So at the same mass, a BH could theoretically generate the greatest pull.
Black hole having strong gravitational pull not even light can escape From it
Neutron Stars and Black Holes are the most dense things in the entire universe. Neutron stars come about when a star collapses and has a supernova. As this happens, the core is smashed with all of the weight of the star put into a single point. Because of the immense pressure, the protons in the core turn into neutrons. This in turn creates a super dense and super heavy dead core of the star it once was. Now even though neutron stars have some of the most immense densities in the entire universe, black holes have them beat. Black holes come when extremely large stars compress their cores so tightly the density of the point hits infinity which creates a black hole.
Hope this answers your question.