Conjunction “As” is used in multiple ways.
Main use of “As” is to indicate the way things happen. So Marathi word is जसा( jasA). Depending on gender and multiplicity of object form will change
जसा-जशी-जसे-जसे-जश्या-जशी ( jasA-jashI-jase-jase-jashyA-jashI) as per आ-ई-ए-ए-या-ई (A-I-e-e-yA-I) rule
e.g.
As you wish, my lord: जशी आपली इच्छा, साहेब ( jashI ApalI ichChA, sAheb )
Do it the same way as he is doing -> तो जसे करतो आहे तसेच कर (to jase karato Ahe tasech kar )

For other usages of “As” refer to the section of frequently used conjunction for that usage. e.g. For usage of “As” as “because”, refer the previous lesson for conjunction “because”.

He as well as me:-
तो तसेच मी ( to tasech mI ),
तो आणि मी सुद्धा ( to ANi mI suddhA )

She sang as well as dance:-
ती नाचली तसेच गायली ( tI nAchalI tasech gAyalI)
ती नाचली आणि गायली सुद्धा ( tI nAchalI ANi gAyalI suddhA)

He or me:- तो किंवा मी ( to kiMvA mI )
Do or die:- करा किंवा मरा ( karA kiMvA marA )

There is no concept of “Nor”, “Neither-Nor” in Marathi.
The neither-nor statement should be converted to alternate statement using “and”; “both”, “as well as” and then translated accordingly in Marathi.
e.g.
“Neither he nor I were interested” -> “He and me both were not interested” -> तो आणि मी दोघेही इच्छुक नव्हतो ( to ANi mI doghehI ichChuk navhato)

If-then statements are discussed separately in Sentence using “If-Then”