rtgs, neft and IFSC

RTGS is interbank transfer for 1-2 lakhs and above.

NEFT is RBI system standing for National Electronic Funds Transfer. RTGS is more expensive in terms banking charges.

IFSC - 11 digit code used in India fund transfers (stands for Indian Financial System Code). The code identifies the bank and the branch (though not all bank branches will have this code; authorisation for EFT must be given by RBI). IFSC is used by both RTGS and NEFT. To look up a code use the code bank.

SWIFT - standard format for Bank Identifier Codes (BICs) and uniquely identifies a particular bank.

NABARD

NABARD is the National Bank for Agriculture and Rural Development. 

nidhi company ka arth (mutual company kae jairsee company hai)

FDI is not permitted for a range of businesses, including Nidhi companies. Nidhi companies are similar to mutuals, in that they take deposits and make loans, but can only interact with their shareholders.