The movie star Sanjeev Kumar (pretty sure) and Shammi Kapoor, Sanjeev is a cop and Shammi is a Don. I only saw it briefly, it was the scene where finally meet after a long time and realize each others profession.

Any help much appreciated.

It's Sachchaii.
Starring Shammi Kapoor, Sanjeev Kumar, Sadhna.

Story line, as you said. Shammi Kapoor gets into crime, due to circumstances, but I don't think he is Don (boss) ?? Or may be he becomes the head of the crime group (dacait perhaps) as time goes on ?? I remember Sadhna on elephant scene in one of the songs ?? I think music is by Shankar Jaikishan.

Thank you sooo much Rana Bhai

Any DVD of this that you know of?

No DVD that I can find - but this youtube clip mentions a VCD.

http://www.youtube.com/watch?v=Ob-c9YRyRLw

Thanks Muz .. ! I hold off for a DVD of it soon or another telecast.

Also one I am waiting for. I think that my Dad had the movie on VHS (or maybe we just rented it) - I remember the songs were really good.

May be it's some other film ?? I dug up my Sachchaaii VHS and Shammi Kapoor is not Don in it and Sanjeev Kumar is not Police Officer. Actually it's other way around although in the college days Shammi Kapoor believes in crooked ways and Sanjeev Kumar is Sachchaaii advocate. After college, they make a bet to meet in 3 yrs to show and settle what they achieved going their preferred/ ideal ways.
(Pran and Helen also have significant role in this film)

I found the film very interesting. Video was 170 min and not sure if it was 4% speed up ?? It was on Esquire VHS from the days when Esquire had started churning up crap PQs (original Esquire VHSs were pretty good in comparison).

I would like to see a good DVD of this film.

it is indeed Sachaai http://www.imdb.com/title/tt0316521/ -- bobby sitara is the name of sanjeev kumar when he becomes don. it's quite a precursor to "the departed" and "infernal affairs"
also, is it inspired from another firang movie?

http://www.induna.com/1000006145-productdetails/

DVD finally out. Correct me if I am wrong but wasnt the film later remade as Lakshmanrekha with Jackie and Naseer?

Oh.. Laxmanrekha with Jackie and Naser had similar storyline as of Sachchaii. Then I should see it.