One is enough. the case is over, get with it.
Most? China has 14 land neighbors and India is the only country which has land disputes with China. You call 1 out of 14 most?
Blunt lie:-
1. North Korea - Strange, but China has dispute with NK, check for Mount Paektu, Yalu and Tumen rivers.
2. Russia - When USSR you fought an war. Since it was a mighty superpower you lost. It is only in 91 just before his dissolution when they were lowest of their military might the treaty got signed.
3. Mongolia - China claims all of Mongolia on historical precedent, while there was tension with inner Mongolia in USSR era. But irony is Mongolia, under Genghis Khan ruled China.By that logic Mongolia should have ruled China.
4. Kazakhstan- Dispute resolved only in 98, only when large gas and oil reserve was discovered. This oil and gas was pipe lined to China.
5. Kyrgyzstan- She did two agreements in 96 and 99. But irony is this was renounced by Kyrgyzstan parliament, even called for impeachment of President.
6. Tajikistan- Resolved only in 2011. China got the disputed land because of the heavy investment she did in the country.
7. Afghanistan- NA
8. Pakistan- Friend who gave up claim of 2000 sq km of territory.
9. India- Holy grail.
10. Nepal- Not much other than that of Mustang region.
11. Bhutan- Bhutanese enclaves in Tibet, namely Cherkip Gompa, Dho, Dungmar, Gesur, Gezon, Itse Gompa, Khochar, Nyanri, Ringung, Sanmar, Tarchen and Zuthulphuk. Also Kula Kangri and mountainous areas to the west of this peak, plus the western Haa District of Bhutan.
12. Mayanmar- NA.
13. Laos- NA.
14. Vietnam- Leave it.
And South China sea. You have now territorial dispute with Japan, Philippines, Brunei..
Finally Taiwan.....
Still you would be telling only India.