Land acquired should be productive also. China's 2/3 land is barren and useless alongwith difficult topography. It cannot sustain population, thats why 1 child policy was started. Check the population density map.:
Half of Pakistan is Balochistan desert, which has no water resources. So again whole Pakistani population manages on
half Pakistani area.
Bangladesh is extremely populated. But has good fertile lands.
But yeah with Nepal and Bhutan we have advantage on geographical proximity. But we wont need it, coz after USA India
has the largest arable land, so it is suggested we will break 2 billion mark by 2100. Yes after that land will be a problem.But China will still not be an option coz Tibetan Plateau and Xinjiang are barren land, so India has to live with this fact.
Other options like land reclamation can be done.