Flights from Mumbai to Cambodia are expensive compared to Bengaluru. Its better to split flight from Mumbai - Bangkok - Cambodia if you do not get cheaper tickets for your date of travel. Considering 4 days 3 nights - 3 Night Accommodation, 1 day Angkor Visit, 2 days exploring around Siem Reap. The day you reach you need to buy 3 Nights accommodation ($60) 1 Day Angkor Pass - ($37)
1 Day Tuk-tuk for going around ($20)
Landmine Museum ($5)
Floating Village Visit ($25)
Angkor National Museum ($12)
Food ($70-100) - Beer and non-veg food is cheap
Misc ($50) - Shopping/Juices/etc.
Visa on Arrival ($30)
So approx $350 + Flights - 20000 INR (return)
===================================
So should be around INR 40-45k. If you need any more details feel free to contact me on FB @ourlifeoutsidecubicle or Instagram @lifeoutsidecubicle
Hey, budget always depends upon the type of stay and lifestyle. For a budget traveller, it will cost you around INR 5000-7000 for a week (per person) in Cambodia.