you need to make a clear mind about what you are going to buy. your inquiry is too vague like someone saying i'm buying a Honda but has no idea which one, it could be a city 2002 exi, a 9th gen civic or a 1992 accord.
First thing you should think about is if you can maintain a German car. it requires high octane fuel, Are you willing to spend tens of thousands every 8000-10,000 km and 2-3 lacs every 30,0000-50,000 km (depending upon use-abuse).
Second, which category are you gonna buy as German cars come in all sizes and engines. 
CLA is four door coupe without proper room for adult passengers in rear, CLS is its bigger, S class twin,
C class and 3 series are the compact ones (also there is audi A3, A4 which are relatively new and uncommon in our market but value for money)
E class and 5 series are the medium to large size one's depending upon model.
S class and 7 series are class leading examples, have most features and a huge body.
3rd are you gonna buy a new, almost new, fresh imported one(easiest to maintain),
an old used one in pristine, mint condition(which costs higher than what dealers would tell you and would still require 2, 3 lacs in within next 20k km so you can experience what a truly maintained German car feels like for the rest of the period you are gonna keep it)
or a used one in abused condition(not recommended as you would always remember it for a lousy drive not worth the money, a white elephant that you'd have to spill money on without any significant benefit).
My recommendation would be to buy a c180(newest model that comes in your budget) without any local mods(rims, wider tyres, jugaars in suspension, elegance package or amg kit is ok) as it'd be your first German car so you can get a taste of its drive and ownership experience. the c180 which' add you have posted looks the right car for you but get it checked by Shahnawaz first and get a quotation of what needs to be changed(all fluids are gonna be changed anyway for peace of mind).
