For both mobile & fixed numbers: (?:\s+|)((0|(?:(\+|)91))(?:\s|-)*(?:(?:\d(?:\s|-)*\d{9})|(?:\d{2}(?:\s|-)*\d{8})|(?:\d{3}(?:\s|-)*\d{7}))|\d{10})(?:\s+|)
Explaination:
(?:\s+|) // leading spaces
((0|(?:(\+|)91)) // prefixed 0, 91 or +91
(?:\s|-)* // connecting space or dash (-)
(?:(?:\d(?:\s|-)*\d{9})| // 1 digit STD code & number with connecting space or dash
(?:\d{2}(?:\s|-)*\d{8})| // 2 digit STD code & number with connecting space or dash
(?:\d{3}(?:\s|-)*\d{7})| // 3 digit STD code & number with connecting space or dash
\d{10}) // plain 10 digit number
(?:\s+|) // trailing spaces
I've tested it on following text
9775876662
0 9754845789
0-9778545896
+91 9456211568
91 9857842356
919578965389
0359-2595065
0352 2459025
03598245785
07912345678
01123456789
sdasdcsd
+919898101353
dasvsd0
+91 dacsdvsad
davsdvasd
0112776654