This information comes coming from an Indian perspective.
There is a Yes or No.
Electronic voting machines are susceptible to being altered, especially if they are connected to networks. The majority of western democracies utilized such machines and because of their connectivity to internet via an internet connection, hackers were able to alter the machines. The large size of their populations permitted them to go back to paper ballots, instead of developing new ideas for EVMs. The only other nation of our size by population has predominantly indirect election i.e the people don’t elect the president. Instead, the people’s representatives choose the president. [1]
The machines used by the Indian Election commission are not connected to any network. This ballot unit(where you cast your vote) is connected only with the controlling unit(which is the one that your presiding official is using) and will soon be connected to VVPAT(Stands for Voter Verified Paper Audit Trail) which is printing an official paper ballot of your votes to be used for audit purposes. My argument is that in order to alter an apparatus, you’ll have to modify its hardware . This is not feasible because of the multiple randomization process and the checking that takes place on every machine, in the presence of representatives from all candidates in the procedure. [2]
Another interesting thing to remember is that, with the addition of the VVPAT the polling booths is able to handle approximately 1400 votes. This is because every VVPAT machine comes with an oversized roll of paper that can print around 1500 slips, of which are used as the calibration is conducted before the representatives of political parties. Because it’s a lengthy process to change the paper roll mid-polling, the maximum number of people who can vote in each booth is approximately 1400. [3]
If I look at the instance of my district in the Lok Sabha (Gautam Buddha Nagar) during the 2014 elections 2014, 11,99,262 votes were cast . the winner took home 2,80,212 votes. That means that 857 voting booths had been utilized ( 1,992,262/1400 = 856.6) However, it’s likely that the actual number was greater due to the low turnout of 60%..
The introduction of VVPAT has transformed this process from a difficult task to almost impossible since the electronic votes can be added to the paper ballots produced by the VVPAT.
Imagine having to alter 857 booths to alter the results of one voter while defying the polling officer and representatives of every candidate. You can then multiply the effort by the amount of seats. This is the amount of manipulation needed to influence the outcome from Indian election in any way.
[1] Elections in China – Wikipedia
[2] https://eci.gov.in/files/file/9405-checklist-for-presiding-officer-february-2019/
[33 No more than 1,400 registered voters per polling location: Election Commission