Welcome to the world of confusion. I was just as confused.
I am assuming that these are two separate locations for installing the TV.
Viewing distance ===> Recommended TV panel size
upto 7 feet windows opposite ===> 32" to 42" - LED recommended unless you can cover the windows with dark/heavy drapes.
14 feet, no window opposite ===> 42" to 50" - Plasma recommended. LED also OK.
You will get 40~42" LED TV (lots of them) in that budget or 42" plasma (Panasonic 42UT50) or 50" plasma (Panasonic 50XT50).
Very large size is not recommended. 42" is the optimum size for this purpose.
Considering all aspects, 40~42" is the best size for you. We shall come to plasma or LED later.
Plasma has best PQ but LED is not way off behind.
I think that LG and Samsung have best ASS (no pun intended).
Plasma or LED
Go for plasma for best PQ, best blacks, best response time, most natural colours, larger size panel, etc. But LED should be chosen if you watch mostly cable/DTH. Indian movies (whether Hindi or Tamil) are not known for intense black levels, details in shadows, very fast action, etc. They are more pomp and show, colourful, bright, song and dance, stinking rich palatial homes, wonderfully dressed characters, etc. Since you watch a lot of such movies, plasma is not really necessary. In my opinion, you are better off with an LED TV.