tourist visa for father

[harbinder79]

Hi i want to apply tourist visa for may father(73 year old).he visited England in 2008 and went back in 4 months time.
my mother passed away last month and i want him to spend some time with my family.will it be a issue as he is living alone in punjab now.i have a sister who lives in delhi.
second question is finances.
my dad don,t own any property, as his house is in my mother name which will take bit of time to get on his name.he have got money in bank accounts from which he get interest income(they are still joint with my late mother).he dont have any other income.do he need to have any property in his name.what document he need to prove his income from interst(he dont file tax).
i am going to be his sponsor.what document required from my side.i have got 2 bed massionate and i am in full time job.